A police superintendent is caught kerb-crawling in King's Cross. Det. Supt. Clark uncovers murder, blackmail and pornography, and his investigation could finish some careers. The investigation into the Michael Carswell case has tragic consequences for W.P.C. Jenny Dean.

Commander Huxtable has been suspended. Det. Supt. Clark is determined to discover why his lover, W.P.C. Jenny Dean, committed suicide, but his enquiries lead back to C.I.B. Finally, he confronts an unexpected enemy aboard H.M.S. Belfast.