PSNI probationer Grace promises to help Angela, whose son has fallen in with a notorious gang. But with undercover agents watching, will she be able to keep her word?

Mo’s side deal goes ahead, risking his relationship with his father. Tommy’s firearms exam is brought forward, and Stevie tries to convince Grace to come back to work.

The team work together after the shooting. Stevie clashes with the spooks, Mo learns the truth about his father, and Grace accepts that she might break her promise to Angela.