To Singer’s credit, it’s bracing to encounter a semi-mainstream horror movie that’s willing (and eager) to subordinate narrative logic to matters of atmosphere.

It's not very developed, so we don't get invested in their scary shenanigans.

Amid unsettling sound design and plotting that is in every sense loopy, questions are raised about nature and nurture, and about human bonds that go beyond the conventional norms of genetics and biology.

‘Cuckoo’ starts off on a weird note and gets even stranger from there, finding a nice balance between a serious sense of dread and an underlying tone of camp for most of its running time.