Probationary PCs Sally Armstrong and Billy Rowan arrive at Sun Hill, where the team are anxious to find the man who stabbed Sgt. Doug Wright. The new recruits are puppy-walked by Nikki and Emma, and the foursome get a call to attend a disturbance at a jewellery shop. After a successful result, they are later called on to deal with a report of stone-throwing at an abandoned factory – where Billy Rowan's first day ends up turning into his last.