Curly has nobody to take to Susan's twenty-first so Sally offers to set him up with her friend Lois Fairhurst. Mike is surprised when Ken invites him to Susan's party. Peter Barlow arrives from Plymouth with his girlfriend Jessica Midgeley. Peter is pleased to be with Susan again but is surprised to find that she's engaged. Curly is depressed when Lois has a cold and can't go to the party. Susan introduces Peter to Mike. Tina Wagstaffe calls at the Yard with a job. Curly thinks that she's beautiful and invites her to the party. He is stunned when she says yes.