SCORE & TIME ATTACK: If you're playing this tomb from the Challenge Tombs section of the main menu and need tips for the various Attack modes, check out these videos from Treeble: Score Attack or Time Attack.

TOMB ENTRANCE: The entrance to the tomb is at the south end of the pool. It's easy to spot thanks to the yellow paint and gilded totems. Swim, then wade, then walk in through the canyon. On the left side of the path is a document (17/27), Last Words (Cult of de la Cruz). A little farther on, you'll pass between another set of gilded totems. If you're doing the Side Mission, Star Crossed/Explore the Local Mysteries, you'll receive a new goal: Examine the Stele. This is a bit premature, though, since you'll first need to find the stele. (screenshots)

FLOODED PASSAGEWAY WITH MORAY EEL: Continue southward. Wade into the shallow pool strewn with debris. When you reach the deeper water, swim down into a flooded tunnel. Watch out for the moray eel ahead. You can avoid it if you swim down into the grass on the bottom then continue along the tunnel staying close to the floor. Or deal with it by swimming straight toward it. The eel will then attack Lara, triggering a QTE in which you'll need to mash the Interact button to kill it with your knife. Afterwards, get air if you need it. Then continue along the tunnel to the south until you can surface near a wooden ladder surrounded by red leaves. Climb out of the water and scramble up the stone ledge into the next room. (screenshots)

FLOODED ROOM WITH GIANT STONE HEAD: Swim between the floating corpses to the left (northeast) side of the room. Climb out of the water and examine the mural (3/4), God of Cocoa (Mam/Pantheon of Gods 3). Turn around and use a rope arrow to pull down the wooden barrier high on the west side of the room. This opens a sluice gate, filling a bucket, which then opens a gate below, causing most of the water—and dead Yaaxil—to flow out of the room through the mouth of the giant stone head. Wade through the shallow and into the stone mouth. Slide down the slope, taking care to steer around the spiky debris piled up on the left about halfway down. (screenshots)

MORE FLOODED RUINS: There are piranhas as well as floating corpses in the pool below, but don't worry yet. If you swim down toward the piranhas, they'll flee away from Lara through a narrow opening just below the surface in the southwest wall. Swim through after them. By the time you emerge in the next flooded room, the fish should be gone. Take a breath. Then swim down and cut the rope anchoring the wooden raft to the floor. When the raft bobs up to the surface, climb onto it and scramble up into the raised opening to the southwest. (screenshots)

BUG NOTE: If the raft is positioned too far from the wall to make this jump, just reload the checkpoint and it should sort itself out.

Climb the muddy steps to find the Flood Basin Base Camp. Gather a few resources and some salvage. Then climb out of this room via the wooden slats in the far right corner. Move through the low tunnel into the tomb proper. (screenshot)

THE THIRSTY GODS TOMB: As you enter the tomb, you get a wide-angle view of a sinister-looking tower. The tomb stele is visible at the top, but there's no obvious way to climb up. The way in is through the gate on the front of the tower, below the surface. There are just two problems: The gate is closed tight, and the piranhas you saw earlier have met up with a few sister schools and now patrol the pool below. (screenshots)

Rather than diving into the water and risking a feeding frenzy, jump down onto the ledge below. Then jump from there to the first wooden raft, then the second raft. From there, you can see a third raft, anchored to the bottom with a rope. It's almost impossible to avoid the piranhas completely, but if you wait until none of the schools are too close to the third raft, then swim down and cut the rope as quickly as you can, you should be able to turn around, swim back to the surface and climb out on the second raft before Lara takes too much damage. (If Lara dies, as long as you've cut the rope first, the game should reload with the third raft already at the surface so you don't have to do it again.) Now jump from the second raft to the third. Now jump from the second raft to the third. If Lara falls short and lands in the water, climb out quickly. (screenshots)

The next wooden raft is near the front of the tower, just to the left of the rope-wrapped ring. Like the previous raft, it's tethered to the bottom with a rope. The piranhas won't come too close to the building, so it's safe to swim quickly toward the tower. Then you can take your time swimming down to the bottom, where the rope is anchored. Cut it and loot the nearby resource canister. Then return to the surface. (screenshots)

Now move to the front right corner of the tower, again staying close to the building so the piranhas don't notice. Swim down and away from the building, staying close to the stepped ledges as they slope downward. Swim along just above the circular carving on the floor, then once you pass it, swim straight down and turn around to spot a little room beneath that circular floor. Inside are 2 salvage crates and a survival cache (7/8). When you have everything, swim back to the surface, again staying close to the tower to avoid the piranhas. Around the right side of the tower, way in the back, near the bottom of the pool, there's some gold ore embedded in the wall. Swim down and pry it out. Then return to the front of the tower. (screenshots)

Swim over to the wooden raft in the corner at the front of the tower and climb onto it. Then climb onto the ledge to the west. (screenshots)

OPENING THE GATE: Follow the ledge around to the left, picking up a few minor items on the way. Jump across the gap and continue past the spinning water wheel. Walk across the log bridge to reach the ledge in the south corner, where you'll find a document (18/27), Testament of T. Serrano (Cult of de la Cruz); a mural (4/4), Thirsty Gods (Mam/Trials of the Gods); a few resources; and a handle. Push the handle clockwise to swing the spigot around to the right as far as it will go. Now instead of turning the wheel, the water fills the large bucket, which opens a sluice gate and lowers the water level in the big pool. (screenshots)

As the water recedes, move to the edge between the bucket and the pillar supporting the spigot. Look over the edge to spot another survival cache (8/8) below the surface. Swim down and dig it up. As long as you stay away from the middle of the pool, the piranhas shouldn't bother you. Surface for air if necessary, then swim through the doorway just west of the cache. Inside you'll find a relic (9/9), another Primitive Doll (Mam/Handmade Dolls), on the left and some jade ore embedded in the wall on the right. Swim back out and get air. Then swim down into the south corner—below the log bridge connecting the ledge with the water wheel and the one with the handle—to find some more salvage. (screenshots)

Surface and swim back to the last wooden raft, to the left of the closed gate and rope-wrapped ring. Jump from the raft to the wall on the left and climb to the top. Follow the ledges back around to the handle and spigot. Jump down onto the wooden ledge near the water wheel's rope-wrapped axle. Stand near the axle and fire a rope arrow into the rope-wrapped metal ring near the gate to tether the ring to the axle. Turn around and scramble back onto the ledge with the handle. (screenshots)

Now pull the handle back to its original position to swing the spigot around to the left so it once again spills onto the water wheel. Don't let go of the handle yet. As the wheel turns, the rope line winds around the axle, pulling the metal ring and opening the gate. If you let the wheel continue to turn, the rope will snap and the gate will close. So, just before the gate opens fully, push the handle back to the right, so the wheel stops turning. The gate should then stay open. (If the rope snaps, just turn the spigot all the way to the right to lower the water level once more. Jump down to the axle and tether it to the ring. Then return to the handle and try again.) (screenshots)

Once the gate is open, you can follow the ledges back around to the gate, then swim down through it without lowering the water level. Or, push the handle all the way to the right to refill the bucket and lower the water level. Then swim along the left side of the pool (to avoid the piranhas) and walk through the gate. (screenshots)

NOTE: If you missed survival cache #7 and the other items on the right side of the tower earlier, you can get them now. (See above.) Just watch out for the piranhas. When I attempted to retrieve the cache after lowering the water level, the piranhas on this side of the pool seemed more aggressive.

INSIDE THE TOWER: In the room beyond the gate, climb the broken stairs, jump across the gap, and pull up onto the ledge at the back of the room. (If you didn't lower the water level, just swim through and climb out on the left.) In the corner is another document (19/27), Alux (Mam/Legends of the Maya). Follow the ledge around to the opening above the entrance. Loot the resource container in the other corner. Then scramble up into the the opening. Outside, follow the wooden ledge around to the back of the tower, looting another resource container and collecting some black powder along the way. Then climb into the doorway and continue up the stairs. Pick up some gold ore next to the ramp. Then examine the tomb stele to unlock the Warrior Skill Sip's Strike, which gives your charged bow shots more power against armored enemies. If you're playing the Side Mission, you'll also receive a new goal: Return to Manu. (screenshots)

EXITING THE TOMB: There are two ways out. If you lowered the water level after opening the gate, start by sliding down the zip line to the left of the stele. If you didn't lower the water level after opening the gate, you can ride the zip line or head back to the Flood Basin Base Camp. This alternate route is covered below.

If you ride the zip line, Lara lands in a bat-infested tunnel and slides down into a cave. Climb onto the stone ledge ahead on the left. Continue to a wooden ledge above a spike pit. Jump across the gap and continue up the slope to another ledge. Climb up, then slide down another slope into a pool. The area with the red vegetation off to the right (southeast) is the way back to the room with the huge stone head. To get out, instead head to the northwest through the flooded passageway to the cave with the moray eel. Even if you killed it earlier, the eel may respawn. You can avoid it by swimming forward along the bottom. After you pass the grass on the tunnel floor, swim upward to surface in the shallow pool filled with debris. Now follow the path back to the big pool southeast of the Mission. (screenshots)

Alternatively, if you didn't lower the water level after opening the gate, once you've examined the stele, jump into the pool. If you aim for the water just in front of the wooden raft nearest the gate, you should have time to surface and climb out onto the raft before the piranhas notice. Jump across the rafts to the jutting wooden ledge in the far left corner. Go through the archway into a dirt-floored room. Use a rope arrow to pull down the wooden barrier on the right. Beyond the barrier is the Flood Basin Base Camp, which you can then use to Fast Travel back to the Mission or wherever you may have left off in the game. (screenshots)