Gold and Okaro decide to mount an obbo to catch pimp John Rutherford in the act, which means sending Best undercover at London's Kings Cross Station. He rescues a young girl, Lorna, from a mugger, and the two start to get on well. When they are approached by Rutherford, he suggests they stay at a squat he knows. Best is suspicious, but doesn't want to leave Lorna in Rutherford's clutches. However, when the support team lose sight of him, Best finds he is in way over his head. At the squat, he is drugged, and wakes up with no memory of the previous night when Taviner and Hollis raid the house. Meanwhile, Ackland and Bradford investigate a domestic violence case involving a husband and wife.