Crime comes closer to home in this finale when forensics worker Kelly Mahon is found brutally murdered in her flat. Ronnie and Sam get straight on the case, and after some investigating, they discover that she took a taxi home. Finding the taxi driver, they're immediately suspicious. However, it's only when an almost identical attack is attempted on Lucy Kennard - who worked with Kelly - that they become certain they have found their culprit. When the police arrive to arrest the taxi driver, he makes a run for it. In pursuit, Sam arrests cabbie Carl Lucas. As they question him, and ask why he ran, he reveals that he had stolen goods in his car. But is he telling the truth? Or have they caught their man? At first, Lucy's evidence seems compelling. But when it's revealed to the jury in court that her relationship with Sam Casey was more than it seemed at first, the whole case looks in jeopardy of being thrown out...
