The London Tram Murders

The murder is an uncanny repeat of their previous case, and their inquiries are complicated by the presence of the main suspect’s doppelganger, Melanie Bradshaw. The brilliant chemistry master student has solid alibis but Shepherd, flying in the face of the contrary evidence, is convinced that the deceased serial killer's sister and Melanie are the same person.

As the killings continue, Vance and Shepherd face increasing pressure from above building. Can they apprehend and bring the killer to justice before more lives are lost?