The team is called to a drive-by shooting outside a London nightclub. They arrive to a scene of carnage with several people dead, or dying.

With the murder of the club manager, the pathologists also determine that the club owner shot his own girlfriend, likely by accident. They also identify an unlikely suspect in the shooting of the club manager. Harry and Nikki confront Leo over his abusive and unprofessional behavior.

Left wing writer Tom Flannery rings for the emergency services when he finds his investment banker wife Bridget dead at the foot of their stairs, lying in an unnaturally large pool of blood. Both Harry and Detective Superintendant Jenkins find the death suspicious as some blood seems to have been cleaned from the wall, making a 'void', but then Jenkins dislikes Flannery's anti-police strand in his writings and she knows Bridget was insured. Nikki believes the death was an accident until Bridget's sister Muriel tells her that the first Mrs. Flannery also died after falling downstairs.

At the coroner's inquest into Bridget's death Nikki and Harry give conflicting evidence though it turns out that a young policewoman made the 'void' when she slipped on the blood and touched the wall to steady herself. Disturbed mental patient Diamanda Yannis,who had previously attacked Tom's daughter Anna, a nurse, was seen at the Flannery house, covered in blood but she dies after a fight with police. Harry has the first Mrs. Flannery exhumed, proving that someone killed her. Tom admits to Nikki it was him,during a drunken argument over his wish to marry Bridget. He also claims that he killed Bridget but Nikki believes he is shielding somebody else.Is he?