undertone

Evangeline "Evy" Babic lives with her terminally ill mother in their family home, doing everything alone while co-hosting a paranormal podcast called The Undertone with her friend Justin, who calls in from London. She has recently discovered she is six weeks pregnant — unplanned, unwanted, loaded with Catholic guilt she thought she'd shed. To cope, she throws herself into the podcast. Justin forwards her ten anonymous audio files and a cryptic message about atonement. They decide to play them live on air.

The recordings are audio diaries from a couple: Mike and his pregnant partner Jessa. What began as Mike documenting Jessa's disturbing sleep-talking spirals — across ten files — into full possession. Jessa speaks in a guttural voice about an unseen child and demands sacrifice. Nursery rhymes warp and repeat. The violence escalates, heard but never seen.

As Evy and Justin work through the files, her house begins to echo them. The same rhythmic knocks. The same rhymes. Her nearly catatonic mother starts reacting — fingers twitching, breathing shifting — in sync with the recordings. Justin, digging into folklore, identifies the entity as Abyzou: an ancient demon tied to miscarriage and infant death, consumed by jealousy of pregnant women. By engaging with the files, they may have opened a channel. Evy is pregnant. The targeting may have already begun.

The haunting intensifies as the final recordings approach. Doors move. A child's cry comes through the pipes. Listeners from earlier episodes make contact, hinting the files have passed through other hands and left damage behind. Justin urges Evy to stop. She doesn't — whether from commitment to the content, compulsion, or some darker pull she won't name.

The last files end in screaming silence. Jessa's fate: suggested, not shown. Justin's warnings go unheard. As the final recording plays, the lights die, the nursery rhyme returns louder than before, and something moves in the room above Evy — in her mother's room.

The film ends in sound and darkness. Evy calling for her mother. Her mother making sounds that aren't hers. A violent struggle on the stairs. A fall. Then nothing. Whether Abyzou possessed the mother and used her against Evy, whether Evy broke under the weight of guilt and grief, or whether the two women destroyed each other with something ancient watching — the film withholds the answer. Evy and her mother have become the next recording in the chain.