Carter is a unique police officer. He only has one name... Not only found in the force in which he works, the Merseyside constabulary. But in the whole of the country. Carter is the head of an elite group of hand-picked officers known as 'The Major Crime Unit.' Together with a very capable deputy, Woman Detective Superintendant Susan Ford. Their job is to investigate severe cases of crime, force-wide, to relieve the pressure from their restricted divisional CID colleagues. Carter returns to his flat after spending a couple of week's leave with his in-laws, Diane and Martin. Sinclair. The parents of his murdered wife, Helen, their two children, and the duty Armed Protection officer engaged in their protection. A heinous crime conducted by the cohorts of a major criminal gang, hoping by committing the audacious crime, both he and the MCU would implode. It had been some four years since her death, and her parents had come to love Carter as their son. He could always use their farm as a bolthole to escape the rigours of his job. On his return he opened his holdall, and as usual, Diane had washed and ironed his clothes. On completion of his domestic chores, he enters the lounge of his flat, carrying a mug of coffee. On the coffee table, he notices amongst his pile of mail set aside by his domestic Kate, an ornate white envelope with silver edges. He opens it and sees he's been invited to a party at the home of his best friends, David and Hannah Robison. He attends the party and is made a fuss by his hosts. It is while he is relaxing with a drink, and viewing the other guests, when his pager activates, he apologises to his friends, saying he must leave. He is collected by DS Phil Watson, when asked what is going on; all his junior officer knows that a body has been found in a local municipal park. And, so, it begins ...