A wildlife volunteer on an uninhabited island off the British coast descends into a terrifying madness that challenges her grip on reality and pushes her into a living nightmare.

When Patricia arrives at a country hotel in Cornwall, she encounters her ex husband Idris, who manages the place with his girlfriend Louise. Things are immediately awkward and the former couple reconnect over a long, messy night where they revisit the past while remaining open to new beginnings.

Catherine and her family recently moved into a converted church. Upon moving in, they have been harassed by an unknown religious stalker, claiming them to be sinners. Pamela, Catherine’s grandmother soon begins to reveal she has secrets hidden to the local church, and not all is as it seems. Each night the Nun returns, and this time, she is looking to claim more than one soul.