Caleb (Domhnall Gleeson), a programmer, is sent to a remote facility when he's given the job of evaluating his company CEO Nathan's (Oscar Isaac) experiment in artificial intelligence - a robot named Ava (Alicia Vikander).

What was supposed to be a routine check turns into much more when Caleb forms a friendship with Ava, who raises doubts as to whether anything Nathan says can be trusted. For his part, Nathan questions Ava's motives, and Caleb begins to wonder if he's doing the testing or if he's being tested himself.