Blue cat opens tomb. Hmm. Where have you seen a blue cat?
Remember the mural covered with sand at the end of tunnel 1? That one had a picture in the middle of it that looked a little like a blue cat.
Go to the end of tunnel 1 and use the brush from the right table in the antiquities tent on the sand. This reveals --
-- a cat-shaped slot. Did you finish assembling the cat amulet in the antiquities tent?
Insert the green cat amulet in the cat-shaped slot to reveal a new tomb, how totally awesome! --
-- at least, until that twit Dylan barges in and triggers a cave-in. Dolt!
How do I rescue Dylan?