The film is set in present-time United Kingdom in an alternate history. Eight candidates dress for what appears to be an employment assessment exam; they enter a room and sit down at individual desks. Each desk contains a question paper with the word "candidate", followed by a number, from one to eight. The Invigilator, a representative of the company named DATAPREV, explains that the exam is 80 minutes and consists of only one question, but there are three rules: they must not talk to the Invigilator or the armed guard at the door, spoil their paper, or leave the room. If they do, they will be disqualified.