Tim is in a custody battle with his ex-wife, when he quits his job. He applies for a job as a civil servant doing data entry, but discovers during the job interview that he has been offered a job as a trainee spy for MI5.

During Tim's first day at MI5 he appears to rescue a homeless man. A social worker assesses Tim's parenting skills, but she becomes a little too friendly.

Tim doesn't like the grade he gets when he hacks his son's report card.

Tim wants to join Marcus's mysterious "book club" so he asks Caitlin to give him lessons in culture.

The new drugs policy leads the Examiner to substitute Tim's blood for his own, which leads to unexpected trouble. Meanwhile, Marcus finds a new vocation.

The day of the custody hearing arrives. Who will stand up for Tim?