When a spate of shootings claims one of Ronnie and Joe's own, Wes Leyton, the pair are left with a race against time as the next target the shooter has in his cross-hairs is CPS boss Henry Sharpe.

Still affected by the death of one of their team, Ronnie and Joe have a new case to deal with when a young mother is stabbed to death in a busy London marketplace.

When a car is pulled from a river with a skeleton in its boot the pathologist reckons both have been there for a quarter of a century and eventually the dead man is shown to be Taylor Kane, one of the first black undercover officers, who disappeared at the time of the Brixton riots.

The body of elderly businesswoman Ranya Habib is found at a suicide spot but foul play is suspected after a neighbour tells Ronnie he heard her arguing with somebody.

Ronnie and new partner Joe Hawkins, who has come from the child protection unit, investigate a gruesome double murder where the victims' hands and teeth were removed.

Philip Gardner, a psychiatrist specialising in troubled adolescents, is stabbed to death and Ronnie initially believes that one of his clients is the culprit.

Unemployed family man Neil Lester is battered to death with a paper-weight in his own home, having convinced his wife that he has been working for the past nine months

Maids find blood-stained sheets but no body in a hotel room, booked with a credit card stolen from businessman Charles Hutton by Rufus Barton, a school classmate and secret lover of Hutton's daughter Georgia.