Before going after the secret, make sure you have unlocked the door, since you'll need to make a speedy exit.

Move to the edge of the doorway overlooking the side of the pyramid.

Step off the edge to land on the flat spot below on the left.

Turn left and take a running jump over two sloping blocks onto the next flat block beyond.

If you turn and look up the pyramid, you can spot a giant beetle a few tiers up. Take a standing jump onto the ledge above to trigger the beetle...

...roll so Lara's back is against the ledge...

...and shoot the beetle when it gets close. This way it can't knock her off the edge.

Turn around and climb up twice more, to the ninth tier.

Now you should be on the same level as the top of the doorway. Take a standing jump over the slope to the ledge on the right side of the door, where you'll find a small medipack.

Take a running jump to the ledge on the other side of the door. Pick up the REVOLVER (or ammo if you already have the weapon). This is the level's only SECRET (65/70).

When you pick up the gun, a swarm of beetles comes out of the pyramid. To escape them, drop down...

...and run through the doors into the pyramid. The beetles will follow but only as far as the load-in to the next level.

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