The art of surveillance is a core skill for any would-be spy. Working in teams, the recruits practice the basics of following targets without being noticed or drawing attention to themselves. The would-be spies are tested as the trainers watch and judge them on their triumphs and failures. For their latest mission, the recruits must use all their spy skills and put their professionalism to the ultimate test in a one-on-one surveillance mission in Brighton. They don't realize until the last minute that their target is actually their closest friend or family member whom they haven't been allowed to see since starting the course. If they allow their personal feelings to compromise the mission, they risk being thrown out of spy school.