The Sea Hides its Dead (en Inglés) - Megan Bontrager

The Descent meets The Ritual in a cult aquatic horror about a group of academics trapped in a sea cave who must reckon with unknowable horrors as they are forced to atone for their greatest sins.

ATONE OR DIE.

Grad student Caro has no idea what she wants to do with her life, but when an opportunity arises to act as a research assistant on an anthropological expedition for her professor and lover, Edward Beck, she doesn't hesitate.

Beck assembles a team of academics and professionals to study the ancient sea-based Cult of the Leviathan, and the expedition descends into the sea caves where the cult are said to have dwelt.

But when the cave entrance collapses, trapping them inside, the expedition will find they are not alone in the darkness. Surrounded by strange artefacts and scattered bones, an ancient trial has been set in motion. One by one, the members of the expedition will be tested and forced to atone for their greatest sin. . . or die.