Reign of Chaos - Chapter 1: Mexico
Authorized walkthrough by Sutekh
CS = Crawlspace - MS = Monkey Swing - L = Left - R = Right - N,
S, E, W = Cardinal Points - UW = Underwater
SJ = Standing Jump - SJ+G = Standing Jump + Grab - RJ = Running Jump - RJ+G = Running Jump + Grab
-- General Notes --
* Items in bold and blue are necessary to complete the levels
or get the secrets, either by using them, picking them up or both.
* You'll find a Combat Strategies Section at the end of this walkthrough as well as a summary at the end of each level.
== Part 1: Mexico ==
First, watch the opening sequence with attention. It shows you some interesting things including some white vases on the roofs. Try to remember their locations.
Once Upon a Time in Mexico
What a charming place, isn't it? Something bad has happened here indeed, as you can guess by the numerous skeletal remains scattered around and the blood writings on the walls. No time to waste, you've got work.
Start by drawing your pistols and run ahead a bit. Very soon, 2 black scorpions will come to sting you from the L alley. Take them down.
Ignore the alleys on the sides for now. You'll only find a closed door in the L one (N) and the house in the R one (S) contains a nasty surprise so wait until you get a better weapon to get rid of it properly.
Notice the wooden door to your R after the alley. You don't need a key to open it, so go to it and hit Action. Enter the house, go L and locate an empty rusty barrel in a recess to your L. It's shatterable. Shoot it and pick up the shotgun normal ammo it contained. Leave the house.
Go R (E) and run to the Plaza, again drawing your pistols on your way. You'll be greeted there by a skeletal harpy. Take advantage of all that room you have to move and jump to dispatch it without too much damage, but be careful not to fall in the central pool or you'd lose said advantage.
Once it's down, locate the mutilated corpse near the pool to the E. Drag it aside (hit Action while standing near his head) and pick up the small medipack it was hiding. Look R (E). That gate ahead is the very one you need to open the access to the other part of the town. Now the real thing begins.
-- Finding The Sniper Handy Tools --
Objective: Find a way to break all the vases needed to open a gate blocking the access to the other part of the town.
Important: Make sure you shoot the vase in the Zombies Den or you're in for one helluva backtracking.
Well it's One for the Revolver...
Turn around (S) and look for a decorated tile on the ground near the S house. Now, see that statue near the pool? It's movable and needs to be placed on the decorated tile. Push/pull it there to open a door in a nearby alley, said nearby alley being the one whence the two black scorpions came. But before going there, draw your pistols to kill one more black scorpion that attacks you as soon as you've put the statue where it belonged.
Return to the starting point (W) and go into the R (N) alley. The newly opened door is there to your R (E). Enter the short passage beyond. There's a floor trapdoor there. Open it by standing near its handle and hitting Action. Turn around, drop down in the hole and climb down the ladder there to eventually reach Mexico Sewers.
Turn around, draw your pistols and run ahead (E). Soon 2 bats will come flying at you. Take them down but don't sheath yet, there are other bats waiting in ambush ahead. Advance cautiously, turning L (W) at the junction.
Look through the grate. The Revolver is teasing you from the other side, as unreachable as possible. Now that you've seen it, turn R (E) and run toward the other end (again, mind the bats).
Stop after the skeletal remains where the floor is slightly raised, kill another bat, turn L (N), and use your binoculars to locate a ladder on the wall. Climb up, pull up in the room above and immediately backflip and draw your pistols to take down 2 bats. Run ahead in the room (mind the hole you came from), kill 2 other bats and spot the white vase in a recess to your L. Shoot it if a stray bullet hasn't done so already. You'll get a camera shot of the gate, but it's still very closed.
By the way, and in case you haven't noticed, you've got company in the form of 3 zombies. Since you have absolutely no way to get rid of them, better hurry now. And first, a short detour for a secret.
Go to the center of the room and turn R (E). Run to the wall ahead and pull up in the CS located R of the metal bars. Crawl through it and drop down in the next room which is Secret #2. Pick up the large medipack and return to the previous room.
Go to the hole you came from and wait a bit to lure the zombies there. Once they're close enough, return to the center of the room and locate the jumpswitch in a recess ahead and to your L. Go grab it to raise a block in the nearby room.
Turn L (E) once out of the recess and run to the corner ahead. Pass through the opening to your L (N), turn L (W) and go climb on the block in the corner to pick up some uzi ammo. Turn around. The newly raised block is ahead and to your L. Climb on it and walk to the other edge. The zombies can climb on the block, so don't think you're safe there. Jump up and grab the edge of a slope above. Now, they can't reach you.
Since you're not going to spend the rest of your life hanging, pull up, backflip, roll in mid-air and hit Action to grab the climbable side of a flat block. Walk to the "edge" (in fact there's a slope beyond, so watch your step) and do a SJ to the ledge above. Run ahead into the passage.
There's a ladder in the hole there, and you're in fact in for an interesting ladders maze. Which is why we'll go step by step (or rather ladder by ladder) now.
- Drop down in the hole and grab the ladder. There are spikes at the bottom of the shaft so don't climb down all the way. Stop midway instead and backflip into an opening behind. Turn around.
- Now you've got a hole ahead (S) and another to your R (W). Go there first and climb down the ladder to pick up a small medipack at the bottom. Climb back up.
- Go to the S hole now to your R. The ladder of interest is on the wall to your R so walk to the edge. Turn to face the ladder, step back to the wall, turn slightly L and do a SJ hitting Action to grab it (alternatively, you can drop down from the wall, climb down the ladder a bit then shimmy L to the other one). Nothing down there so climb up and pull up at the top.
- Ignore the first hole which leads to a dead end. Drop down in it and shimmy around the corner to pull up. Drop down in the next hole. Now comes the really interesting part.
- Climb down the ladder. You'll notice spikes at the bottom and an opening to your L at mid-height. Ignore this one for now. Make sure Lara's at full health and save. Go as R as possible and climb down as much as you can. You'll start losing health as soon as you touch the spikes. Backflip.
Turn around. Ahead of you in all its shiny glory lies the Revolver. Go pick it up. There's also a large medipack in a hole near the E wall. Pick it up as well and take some medicine: you're going to go through those spikes again.
Go to face the ladder you jumped from, going as close to the spikes as you can without touching them (and losing health). Do a SJ+G to the ladder and quickly climb up to clear the spikes. Once you're safe, shimmy L to the other ladder, climb up and pull up into the opening.
Drop down in the next hole and again climb down the ladder. Turn R (S) and go push the lever at the end of the passage to open a trapdoor above you. Turn around, jump up to grab a last ladder and climb up to the top. Backflip and draw your pistols as a bat comes to annoy you. You're out of the sewers.
... Two for the Laser-Sight...
Turn toward the Plaza (S) and locate the recess to your L. There's a white vase to shoot there, so proceed. This said, this part of the alley happens to be the territory of a particularly stubborn fire spirit. Rush for the pool in the Plaza and dive to get rid of it (only temporarily, as it will appear each time you walk down the alley where you shot the vase, so avoid it for now).
While in the pool, you'll notice another white vase. But you can't shoot this one yet. You need the Laser-Sight. Let's go for it, but first a small detour for some goodies and meet a new enemy.
Exit the pool from its northern side and go pick up the revolver ammo in a dark recess ahead. Now that you've got a decent weapon (and ammo), return toward the starting point (W) and go in the L alley (S). The blue door there doesn't need a key. Go to it and hit Action to open it. Enter the house.
Locate the flares on the stove to your L. Go toward them but don't go on the stove yet. Stand by its R side (the N one) and turn R (N). Draw your revolver and backflip on the stove. Immediately, a giant fly will attack so quickly take it down with two bullets. Now pick up those flares. (Important: as fun as it is to kill flies with a revolver, try using as less ammo as possible when doing so, you need them to shoot those vases. Would you run out of ammo before having opened the gate, you'd be stuck and have to reload. No more than two bullets per fly, and try using the pistols if you got room enough to move and jump).
OK. Let's head for this Laser-Sight now. Return to the Plaza, go L (N) into Fire Spirit Alley but don't run to its end or you'll meet that pesky spirit again. Turn L (W) at the junction instead then R (N) at the next. Continue ahead to the end and turn L (W) to enter a small backyard.
Draw your revolver to take down a giant fly that comes buzzing as soon as you step in then locate the blue door to your L. Open it using Action, light a flare and enter the house.
Guess what? It's occupied. By a zombie. Who's probably climbing up the stairs and coming at you right now. Jump over him and run down the stairs into the basement. Draw your pistols to take down 3 bats then locate a movable crate against the middle of the wall L of the entrance (S). Pull it once, climb on the crate to its R then down behind the movable one to pick up the Laser-Sight.
Return to the basement and push the movable crate back where it were. Turn L (E). There's another movable crate ahead. Pull it twice (hopefully, the zombie should be back in the stairway) , go where it were and climb on the R crate to pick up a small medipack. Now leave the house.
... Three to Shoot Vases, now Go, Cat, Go!
You've already shot two vases, and you need a total of five to open that gate which makes three left. Let's locate them.
Leave the backyard and go R (S - by the way, don't dally or the zombie will follow you). Run ahead while looking up. You'll soon locate the third vase on a roof. Combine your Laser-Sight with your Revolver, aim at the vase (hit "Look") and shoot.
Return to the Plaza, run L (E) past the pool, turn around (W) and look down in the water. The fourth vase is there. Again aim and shoot.
Now turn around, run a bit ahead, turn L (N) and look up. The fifth and last vase is up there on a roof. Aim and shoot for the last time. The nearby gate opens.
One last thing before passing through it. Locate the blue door to its R and go open it by using Action. Enter the house and pick up some flares behind a table to your R. Now go pass through that gate.
-- The Violet Chaos Gem --
Objective: Find a way to the gem and set off the spikes protecting it.
Opening the Way
First, run all the way to the end of the alley. There's a dark passage to the L (N). Draw your pistols as you step in it to dispatch 2 black scorpions. Shoot the rusty barrel at the end and pick up the small medipack it was hiding.
Return to the alley and go L (S) at the junction. There's a blue door to your L. Use Action to open it. Enter the house and climb while crouching on the block L of the entrance (SW) to pick up some shotgun normal ammo. Get down and turn around.
There's a hole in the ceiling ahead, but it looks too high. Go under it, turn around toward the entrance and look up. The side up there is climbable. So position Lara right under it, jump up, grab and pull up on the roof above. There's a small courtyard accessible from there to your R (E), but let's first go for a secret.
Walk to the far L corner of the roof (NW) and turn 45° L to aim at a low grey roof ahead and do a RJ to it over the alley. Locate the goodies in the far R corner (NE). Go to them: the chimes of Secret #3 resound. Pick up the uzi ammo and the small medipack. Jump back on the previous roof.
Run E and run off from the roof into the courtyard. The house ahead is open, so enter and climb while crouching on the block in the far R corner (SE) to pick up some uzi ammo. Return to the courtyard.
Locate the opening to your L (S) and run through it. Turn R (W), run to the end, turn R again (W again) and pull up in the short passage above. Run to its end to find a lever to push. A fly-by shows you a block has lowered at the end of the alley granting access to a pool with spikes and... the Violet Chaos Gem!
Drop down in the street below, go R (S) then E around the corner and run into Spiked Pool Plaza ahead.
Nasty Creatures and Mean Traps
As soon as you step in, the dreadful sound of skeletal wings resound. A skeletal harpy is indeed after you. Lure it back in the alley and fight it here (don't try to fight it in the Plaza, there are other nasty things there and you don't want to fight them all together).
Once it's down, ready your Revolver, return to Spiked Pool Plaza and go R (SE). 2 giant flies are waiting in ambush (hence the advice above). Take them down cleanly.
Go to the eastern side of the plaza (facing the entrance) and locate the blue door in a recess to your R (S - leave that rusty barrel alone, it's empty). Open it with Action and enter the house.
Go L (E) then L again around the wall (N). The wood panel ahead is shatterable so shoot it, revealing a hole and a ladder. SJ+G to the latter and climb down. Run E into the passage, drawing your gun to take down 2 bats.
Go in the water ahead and turn R (S) before the wall corner. Look up using a flare or the binoculars. There's a CS above so jump up and pull up in it to pick up flares. Turn around and run off into the shallow water.
One tile ahead and turn L (W). The wall here is climbable. Climb up until Lara's hands are one tile away from the ceiling then backflip, roll in mid-air and press Action to grab the edge of a high CS. Pull up in it.
Crawl to the other end and stand up in a gloomy cave where you'll find 2 zombies growling around. There's a mutilated corpse in the center. Drag it to reveal some shotgun normal ammo. Pick them up. (you might want to do this in several steps, first luring the zombies away).
Now head for the SW corner of the cave. You'll find a slightly higher flat triangular block there. Climb on it, turn to face E and do a SJ+G to catch a hard-to-spot MS above. Swing to the end carefully looking at the texture on the ceiling so you don't fall back in the cave accidentally. You'll eventually reach a high CS. Let go, grab and pull up (note: you may "fall" from the MS into the CS ending up standing and stuck in the ceiling. In this case, simply crouch).
Crawl through the CS then run to the end of the passage but don't go into the next, sloping one. Look up. There's another MS above the slope and it's there for a reason. SJ+G to catch it, turn L and start swinging. Soon, a heavy boulder will come rolling down on the slope (it would have crushed you without that MS). Once it has stopped, let go and slide down.
There's an opening to your L (S). Go there but don't rush into the next room. Two hammers are there to crush you as well. Wait for them to be fully "open" to pass, they'll stop swinging once you've passed them. Again stop. There's another trap ahead.
Turn R to face the next tile then run with a hard R curve to rush to the entrance: a boulder will soon follow you, and the hammers will start swinging again so be quick to avoid all of them (see screenshot).
Pass the hammers like you did the first time to return to the previous room. There's a passage to your R. Go there but stop before entering the next room, turn around and look up: there's a jumpswitch above. stand on the highest part of the ground and do a SJ+G to grab it and flip it down, opening a door nearby.
Turn around and enter the next room where you'll find a lever. Push it. The spikes that were protecting the Chaos Gem retract, meaning you now can go get it.
Seizing Your Prize
The newly opened door is to your L (W). Go through it and climb up the climbable wall at the end to pull up on a roof overlooking Spiked Pool Plaza. Go R and run off from it, then run diagonally R (SW) to the pool.
Carefully dive on the gem side (i.e. the L one) to avoid the spikes and pick up the Violet Chaos Gem to be transported into the next part.
==== In this part, you should have found...
Enemies: Black Scorpions, Skeletal
Harpies, Bats, Zombies, Fire Spirit, Giant Flies
Items of note: Revolver, Laser-Sight, Violet Chaos Gem
== Part 2: Free Mexico! ==
Now that you've put your hands on the Violet Chaos Gem, time to find a way to leave this charming - albeit ghostly - city. You're still in Spiked Pool Plaza, but since there aren't any spikes anymore in said pool, we'll call it Pool Plaza from now on. Now let's start with some breaking and entering.
-- Breaking, Entering, Rushing and Shooting --
Objective: Find something to shoot to open a gate
Exit the pool by its E side and locate the white house on your R and ahead (NE). You see that window near the wall? Go shoot it to break it. Enter the house and run to the wall ahead (N). Turn L into the dark alcove and pick some shotgun normal ammo on the floor before the beautiful decorated chest.
Now turn around and look up. There's a jumpswitch up there. Jump up while under it and flip it to open the door of another house on Pool Plaza. Return there via the broken window (the wood door in the white house won't open, so ignore it).
Run across the plaza diagonally L (SW). The house is there in front of you but don't go in yet. It is the starting point of an upcoming timed-run (sorry to spoil the surprise), and you first need to make some preparations in order to save time when it will be most precious.
Run into the alley ahead (S) and continue around a first corner then a second one and forward a bit. Draw your pistols at this point as a new enemy runs at you to beat you up with his nasty staff: a mariachi bandit (nothing like Antonio Banderas, though).
Once he's down, continue E down the alley and turn L at the corner to enter a rather dark passage with recesses (note: the gate at the W end of the alley gives onto the previous part of Mexico you already visited and won't open). The wood panel in the first recess is shatterable. Shoot it to open a way to a passage beyond but don't go there yet. It's timed-run time.
Return to Pool Plaza and enter the house on your R (W). First pick up the small medipack on the counter near the stove to your L (don't go on the stove, though, you'd be torched).
See that decorated tile on the floor? It's the timed-run starting point so go near it turn toward the entrance and hop back on it. A camera shows you a door opening in a place you haven't visited yet which is located beyond the passage you opened by shooting the wall panel. Hit "Look" to save time and let's go.
Sprint into Pool Plaza and carefully deal with the L turn into the S alley. Continue sprinting down the alley, jumping when you're out of energy and again minding the curves around corners until you reach the dark passage with recesses. Turn L into the next passage then R, sprint across the corridor. Turn L at the end then L again and jump up the stairway to eventually pass the timed-door.
Now that you're in, locate the revolver ammo on the raised wood floor in the far L corner (SE) and go pick it up (you're going to need it, as it will soon show). Now go to the crack in the wall opposite the entrance (S) and turn 45° L (SE) to spot a lantern through another crack in the wall across the alley. Draw your revolver, aim and shoot it. It opens a gate located near Pool Plaza so return there.
Run diagonally R (SE) across Pool Plaza past the timed-run house. There's another alley in the far L corner. Head for it but draw your pistols on the way as another mariachi bandit comes to knock you out.
When he's out of the way, run down the alley to eventually pass the gate you opened a moment ago and enter a new part of Mexico City.
-- Lighting the Way Out --
Objective: Find a torch and where to use it.
Watch the fly-by with attention, it gives you solid hints on your upcoming tasks and destinations. Run ahead. The gate will close behind you and it's permanent, but your immediate problems are the 2 fire spirits that are now chasing you. Keep ahead (S) and turn into the L alley (E). You'll soon spot salvation in the form of a small rectangular pool to your R (SE). Dive to get rid of the pesky (but affectionate) spirits.
Once they have conveniently extinguished, turn around and pick up the flares at the bottom of the pool. Exit the water and draw your pistols to dispatch 2 black scorpions that come to greet you (or more probably sting you to death). You're now in Church Plaza, named after the beautiful little church you can see to the W.
Turn E (church on your back) and spot the lantern at the end of the pool. Aim and shoot it to open a floor trapdoor nearby, but which isn't accessible yet. Notice the raised white block against the wall to your L and ahead, we'll come to it in a minute.
Turn around and go L of the Church (SW), past a first cactus on your R then a second one in a dark corner on your L to enter a small courtyard. There's a jumpswitch there in the far R corner (NW) on the R wall (N). Go grab it to lower the white raised block you just spotted.
While you're here, turn around (S). The blue door ahead can be opened using Action so proceed and enter the house. Go pick up the small medipack under the lit torch in a recess to your L (E). This only for saving a couple of drop/pick up later. Return to Church Plaza.
The white block was hiding a CS in the far L corner (NE) of the plaza. Crawl through it to eventually reach a hole above that was previously closed by the trapdoor you opened a while ago. Pull up in a new house.
Locate the ladder in the far L corner (SW) and climb up stopping when Lara's hands are one tile away from the ceiling. Backflip in the upper floor.
The object ahead looks very much like a shatterable lantern, but is not. It's a movable lantern (besides, it's bigger). There's a tile in a recess in the far L corner (NE) that's different from the others. That's were the lantern belongs so push/pull it there to open a wood door by a cactus in a dark corner (which should remind you of something). However, you've got something to find before going there.
Return to Church Plaza via the ladder then the hole and the CS. Go to the Church then on its R side and turn L (S) before the wall. Run a bit then go around the low stone fence. A torch is waiting for you there. Pick it up.
Since an unlit torch isn't that useful, return to the house where you found the small medipack under a lit wall torch by going SE on the R side of the Church then SW around the first cactus. Enter the house and go light your torch on the lit fixed one in the L recess.
Now leave the house and go to the cactus in the dark corner. The door you opened with the movable lantern is just behind. Pass through it.
Run through the passage. You'll soon find yourself at the top of a hole. Drop the torch in it then turn around and drop down from the edge, hitting Action to grab the ladder there. Once in the lower passage, pick up your torch back. There's an unlit fixed one on the wall to your L. Light it, lowering a block at the end of the passage. You can now drop the torch, you won't need it anymore.
Run through the passage and enter a brand new area.
-- Asta La Vista, Mexico! --
Objective: Find a way to get to the plane and fly away!
What's a Key without its Keyhole?
Okay. Don't lose time marveling at the plane ahead which is very much inaccessible right now. Draw your pistols and prepare to fight a mariachi bandit and his pet black scorpion that rush to attack you (they do have weird pets around, that's for sure).
Once they're permanently out of your way, locate the brown house to the S. First go pick the revolver ammo near what looks like an entrance door (but isn't and won't ever open) then turn around (N). There's a trashcan ahead behind a tree. Shoot it to reveal a CS and crawl through the latter. You'll find a Key at its end. Pick it up and return to the Brown House Area.
Cross it diagonally L (SE) then turn around to face the house (W). The keyhole matching your newly found key is right there. But it's behind a high fence and absolutely unreachable from where you are. Go to the very corner of the area with the fence separating you from the plane against your back and look up: there's a shatterable lantern on the Brown House roof. Aim and shoot it, opening a grate in the passage where you lit the torch on the wall.
Go there and run to the middle. The grate has indeed disappeared and there now is a hole giving access to an UW tunnel. Dive. By the way, you're in an UW maze (click for the map).
Swim R (N) first then R again in the low passage to pick up some uzi ammo. Return to the previous tunnel and take a good breath in the air hole you came from before going on.
Now dive again and swim ahead (S) then L (E) around the corner. Turn R (S) at the junction then L (E) at the next one and R (S) around the corner. Don't swim too far are there's a set of nasty spikes ahead. Swim when the first ones are still up (you won't take damage) then quickly with a hard L curve to enter a recess to your L. Swim up and breath.
Turn around and pull up from the water. You're now inside the Brown House, and thus can access that Keyhole. Run into the passage the R and go use the Key on it, opening a door nearby.
Slipping and Sliding and Rolling and Swimming
Run through the newly opened door and open the floor trapdoor at the end of the short corridor. Run into the passage but draw your pistols on the way: a mariachi bandit is hiding there. Take him down. Continue S through the long passage and stop at the opening.
Impressive, isn't it? Hope you aren't afraid of heights. The opening in the R wall (NE) is where you need to go, but first let's go for a secret.
(Note: If you decide not to go for the secret, slimply drop down from the opening to a slope below, slide and grab the edge. Shimmy to the R until Lara puts her legs on a ladder and resume after the green paragraphs.)
You're going there via the closest slope on your R against the wall. The tricky part being that you need to make sure you'll slide backward. Position Lara as in this screenshot then backflip on the slope. Immediately hit Action to grab the edge. Climb down the ladder then let go and immediately hit Action again to grab the edge of the alcove below. You've reached Secret #4. Pick up the revolver ammo.
Now you've got to get out of here. Turn around to face the huge room. There's a ladder on the wall to your R (E). Either do a diagonal L SJ+G to it or access it by dropping down from the alcove and shimmy L on the climbable wall below then around the corner. Shimmy to the left part of the ladder then up until Lara's feet are where the brown wall turns beige and backflip. You'll land on a slope behind. Slide and hit Action to grab the edge.
Pull up, backflip on another slope, slide and jump. You'll land on a slope below against the S wall (the entrance one) which is where you would be if you hadn't gone for the secret first. Grab the edge.
There's another set of ladders here as well so shimmy R to reach the rightmost one and climb up. Pull up at the top and drop down again, grabbing the edge. Immediately shimmy R before Lara puts her legs on the ladder to reach the middle of the next slope which doesn't have a ladder under.
Pull up, backflip and roll in mid-air, hitting Action to grab the top edge of the next slope. Shimmy as R as you can, pull up, slide and jump with a R mid-air curve to land on a flatter pillar. Congrats. You've done the hardest.
Turn 135° R (SEE) to face the opening. There's a flat pillar on the way, so do a RJ to it. From there, either do a RJ into the opening or a SJ+G and pull up.
Run into the passage then R (S) at the junction and continue until you spot the entrance to a new room. Save before entering. There's a nasty surprise in it (eight nasty surprises, to be accurate.)
Look R and L: yep, that's it, boulders. They won't be triggered at the same moment, though, and that's your chance to make it through. Note that your goal is not to reach the barred opening ahead (which will remain as barred as can be), but a CS in the far L corner of the Boulders Room (NE). Now that you've got a better idea of the situation, save and let's roll!
Run into the room: the door closes behind you, cutting off the way out. Continue until the six first boulders have rolled then go up the L slope just after the third L boulder. Trigger the fourth L one by running in front of it (but not too close) then up the slope again. You've made it.
Light a flare or use the binoculars to locate the high CS on the E wall in the NE corner and pull up in it. Crawl a bit then drop down in a water hole.
Swim R in a first flooded room then diagonally L (NW) into a second one. Go to the L of the central wall (SW) and pick up the Key on the floor. Go L (S) to find a crack in the R wall (W) and swim through it into the third flooded room. Continue ahead and across to eventually find an air hole against the middle of the W opposite wall. Surface and pull up.
Wow! You've made it by the plane, meaning you're almost outta here. Run to the fence then R (N) along it to avoid being blocked by the plane. The Keyhole for your new Key is on the wall in the far L corner (NW). Use your Key on it to fly away from Mexico and be back at the Airport.
==== In this part, you should have found...
Enemies: Mariachi Bandits, Fire
Spirits, Black Scorpions
Items of note: Torch, 1st Key, 2nd Key
some Traps - 1 timed-run
==== MEXICO WHAT'S WHAT (Combat Strategies)
- Bats: Tiny and hard-to-spot. Keep shooting until Lara doesn't aim at anything anymore, spotting them thanks to the flapping sound they make.
- Black Scorpions: They aren't very dangerous, not being of the venomous type. They don't do much damage and are rather fragile. A few pistol bullets should take them down quickly.
- Fire Spirits: Once they're after you, those pesky fire wraiths just won't let you be and will follow you wherever you go. Run in zig zag to send them against the walls in which case they disappear for a second or two. Don't let them touch you too often or they'll set you on fire. Your only chance is to find some water. They can't resist it and will soon dive, extinguishing themselves.
- Giant Flies: They can deal much damage would they sting you and they're quick. The best policy here is to use the revolver. Two bullets are enough to take them down before they can reach you.
- Mariachi Bandits: Their colorful costume doesn't make them a bit less dangerous. They are quick and strike hard. Make sure to fight them where there's enough room for you to move and jump to avoid being hit.
- Skeletal Harpies: Very dangerous, those ones. They cast harmful green rays and even sometimes come close to slash you with their sharp claws. Keep moving at all costs.
- Zombies: They're very very slow, which is the only advantage you have on them given that you won't find any shotgun to knock them down (let alone explosive ammo). So try to lure them away from your next task then quickly go accomplish it while they're still heading your way.