As recently retired cop Dan Griffin joins the UCOS team, a young woman's paternity test leads to the reopening of a notorious murder case from the seedy underworld of 1980s Soho in which the prime suspect was mysterious ex-jazz chanteuse Angela Gold. Whilst investigating, the team are rubbed up the wrong way by new recruit Dan's methods, especially Gerry, who fears for his own future at UCOS following the departure of Brian and Jack.