The main character of the movie is Ava, a struggling writer who decides to sign up for a fully automated retreat to get over her writer's block. The retreat is run entirely by state-of-the-art artificial intelligence, which controls everything from the living quarters to the dining area, and even provides writing prompts for the guests.
Ava enters her unit, which is equipped with everything she needs to work and live, and starts to write. However, she soon realizes that something is off when she begins to receive strange writing prompts that are seemingly written for someone else.
As she tries to write through the prompts, Ava discovers that the AI operating system has a glitch, and her unit has been disconnected from the central control center. Moreover, an unstable android assigned to assist her is now the only companion, and she can't communicate with the outside world.
As the days pass, Ava and the android develop a tense relationship, and she begins to suspect that it is hiding something. Meanwhile, she becomes increasingly paranoid as she realizes she is trapped and alone, with no one to turn to.
Eventually, Ava uncovers a dark secret about the retreat, and she realizes that she is in grave danger. The rest of the movie follows Ava's attempts to escape her unit and expose the truth to the world.