Plot

A video artist looking for work drives to a remote house in the forest to meet a man claiming to be a serial killer. But after agreeing to spend the day with him, she soon realizes that she made a deadly mistake.

Sara's a video artist whose work primarily explores the intimacy of lonely men. One online advert intrigues her so much, she replies, thinking she may have found the subject for her next project. She drives to a secluded house in the forest, where a man claiming be the advert's poster greets her; and as he said in the posting, he claims to be a serial killer (Mark Duplass). Unable to resist the chance to create a truly shocking piece of art, she agrees to spend the day with him. But, as the day progresses, she realises she might've put herself into a position from which she can't escape.

A prolific serial killer, using the name "Aaron" after a previous victim, finds himself dissatisfied with his killings and undergoing a midlife crisis. When his latest ad for a ideograph lures YouTuber Sara to his remote cabin, Aaron changes his approach by admitting he is a serial killer who will let Sara live for the next 24 hours if she records a documentary on his life. Sara, doubting his revelation, agrees to film Aaron in the hope that the video will popularize her unsuccessful web series about eccentric Craigslist clients.

Over the course of the day, Aaron struggles to intimidate Sara, who plays along with his various eccentricities. While Sara continues to doubt that Aaron is a serial killer, Aaron informs her that he intends to conclude the documentary by having her kill him. He eventually manages to horrify Sara by staging a suicide attempt, which almost causes her to leave. However, after Aaron reveals that his life was not in danger, she remains to hear Aaron share intimate details about himself, culminating in the two sharing a kiss.

Aaron brings Sara outside to announce that the documentary will end with them committing suicide together. Sara attempts to escape when she sees Aaron stab himself in the stomach, but Aaron stabs her and drags her into an open grave he dug. As Aaron gives a closing monologue, a still-alive Sara emerges from the grave and strikes him in the back of the head with a shovel before fleeing.

Afterwards, Sara is recorded in public by an unidentified individual whistling a tune heard in Aaron's videos. When Sara notices the individual filming her, the camera abruptly cuts away.