Whilst the sniper claims another body, a French lorry driver, there are fears that he may next target a school and Thomas rushes to ensure his daughter's safety. Drake calls a public meeting to pass on police progress, whereat Martin Cross's brother Ian praises him. Nikki however believes that Cross may have been the only intended victim with the others slaughtered to give the impression of a serial killer. Jack learns that Cross regularly assaulted his wife and teen-age son Craig, who hated his father, and Craig has bullets in his bedroom. Nikki and Jane now feel that Craig was working in tandem with the murderer but when the sniper strikes again Craig is standing next to the victim. They start to wonder if Martin Cross was the only person the sniper wanted out of the way and how many were working with the killer.

Nikki and Jack are called to a tube station where a homeless ex-soldier has fallen under the wheels of a subway train. Leaving the station hotel receptionist Lana Sutherland meets another homeless man, Owen Hanmore, whom she invites to stay with her, becoming his lover. Meanwhile a series of murders occurs with no visible link, beyond the fact that all the victims had used the same tube station.

Whilst fibres under the nails of the latest victim provide a link the the St Jude's homeless hostel Lana is interviewed as a formality and states that Owen Hanmore was outside the tube station at the time of the first death and must thus be innocent. Clarissa, however, finds evidence of Lana's prints on the victim's phone and Lana and Hanmore are both increasingly under suspicion as they locate Lana's child and attempt to kidnap him. The child will provide a link to the murders whilst Nikki helps Luke to come to terms with his own past.