Jonesy is missing, and the general consensus is that he has run off with Donna. Only Susie is suspicious, and rightly so - since he has been shot and wounded, and finds himself being held captive by Louis Chang.
Tom is at first unwilling to believe Susie, and is too busy with the investigation into police corruption into St. David's.
Frustrated, Susie has no choice but to go undercover unoficially and Ben - of course - agrees to help her.
Tom and the team investigate Inspector Falcon-Price but the evidence soon proves that he isn't guilty, and neither is Lucy Wu - who both Amy and Jonesy were suspicious of.
As the day comes to a climax, Susie and Ben find themselves in a dangerous situation which they survive, but she ultimately breaks up with him. Jonesy has to do the same to Donna, and has her arrested. And Amy is stunned to learn that her friend Andrew Reid is the real corrupt cop at St. David's.