A joint investigation begins into all four murders, but questions arise over the competency of the Welsh senior detective. Another murder back in Bristol breaks all the patterns of the previous killings--and comes uncomfortably close to Mowbray's family.

The police pursue a number of leads, but Mowbray strongly suspects Robert Jackson, a delivery driver with a previous record of violence against women. Mowbray's boss disagrees, however, and the detective must decide whether to charge Jackson.