The cave beckons.

Deep in the rainforest of a southern resort island, where bones of forgotten soldiers abound, another corpse is nothing special.

A young couple grieves the death of their young son, but the husband sets out in search of a waterfall said to bring those who see it newfound happiness. The wife is a skeptic, opposed to the trek, but "anything to start afresh," he says, so they try it.

Anything . . .