Commander Blake is in a very precarious position, professionally and emotionally. Her sister Sara is in hospital, dying of cancer, and her highly publicised relationship with the convicted killer James Lampton is now the subject of an official police enquiry, being conducted by Deputy Chief Constable Stephen Blackton, aka 'BLACKDOG'. It's no wonder Blake having panic attacks and dreadful nightmares, nor that she has started psychotherapy under Dr Jane Wellesley to help her cope with them.
Blackton has another remit: to investigate the shooting of Lionel Cripps by the SO19 unit. As Blake's internal enquiry failed to exonerate the officers involved, including DCI Hedges, she is now caught between a rock and a hard place. When Hedges and his pal DCS Branton propose the three of them show a united front, Blake goes along with it.
Graham Warner, the SO19 officer who actually shot Lionel Cripps is Blackton's first port of call. Graham refuses to discuss the matter at home where Blackton has doorstepped him; instead he drives off. Blackton moves on to the Cripps' house, where Lionel's widow, Kathy, gives him a piece of her mind. Blake has had an unexpected call at home too, from Ken Miles. She fended him off after their one night stand but, having just buried her sister Sara, Blake is now quite pleased to see him.
The murder squad is attending a crime scene: a dead man has been found in a park. When Hedges arrives, he identifies him as Graham Warner. A shocked Hedges goes to Branton and they contact the SO19 unit to ensure ranks are firmly closed. All the guys in the unit are very jumpy now the Cripps enquiry has been reopened; plus Graham had rung round all of them in a panic, after his encounter with Blackton. Eye witness reports suggest that Graham might actually have been killed for his mobile.
Blake is covering her tracks too by pressuring her old friend, retired DCI George Hart, to get rid of the gun she used to force a confession from Lampton. She also insists he make sure there is no evidence on his laptop of the illegal surveillance the two of them set up in Lampton's flat. It's already too late on the second count; a search warrant has been issued for George's flat, and the laptop is now in Blackton's possession.
When Blackton discovers all the material has been wiped, he takes the laptop straight to the NHTCU, where Ken Miles is very interested to hear what the senior officer wants, and wastes no time passing the dynamite information to Blake. It is now imperative that Blake gets her gun back. George got as far as his car with it, but then left it in the glove compartment when his car wouldn't start. Blake now leans heavily on her junior staff officer, Browning, to retrieve the gun for her.
Browning heads off to the lock up. She's on her mobile to Blake from George's car saying there's no gun there, when Blackton appears from the shadows. A shaken Browning returns to Blake empty handed. Back in his hotel room, Blackton is on the phone to the police gun registry, reading out the serial number from the gun he's holding. It's registered to Blake.