A young woman is found murdered near the city's red-light district. Her husband quickly becomes the chief suspect, but DC Mowbray has his doubts. Meanwhile, the detectives learn about the brutal murder of three prostitutes in nearby south Wales.

Tensions deepen between Mowbray and his wife, as the police launch their investigation into the latest killing. The murdered woman, a student, worked part-time at a pizza restaurant, where the detectives establish a link with the first victim in Wales.