Holmes investigates when a woman is attacked in her flat and left for dead in a particularly violent domestic violence case. She initially suspects that the woman's landlord, Jamie Morgan, is responsible for the attack, but when she catches the woman having a row with her boyfriend, she arrests him for criminal damage, unaware that she has inadvertently jeopardised a surveillance operation on a major drugs dealer. As Merseyside area drugs become involved, Holmes manages to locate the factory where the drugs are being produced, but a sting set up to catch the villains in the act takes an unexpected turn when they become involved in a violent shootout, and take a young boy and his mum hostage.

Stanton is desperate to be discharged from the Beech case due to her love for Boulton, but Hodges assures her she is doing well. Boulton accepts a free night at a plush Docklands hotel, and invites Stanton to join him. Sure enough, as the pair settle down for their evening of luxury, an assault and robbery at the hotel sees Sun Hill officers arrive to investigate, and their night is ruined. The next day, CID investigates the theft of a laptop computer, and Beech is intrigued by reports of a "mystery blonde" sighted fleeing from the hotel. Horrified that Beech could have discovered their affair, Boulton and Stanton send Beech to the other side of London on a wild goose chase while they solve the case themselves.