15-year-old Johnny Delgado, who lives with his Mexican mother in a flat on the 17th floor of a south London tower block, has set up a business as a private detective, following in the footstep of his father, a policeman killed during a drug raid several years before. His first job is to find out whether gang member Lee Kirk is cheating in his girlfriend, Carly. She pays him £50 for five hours’ work. A simple job, and easy money, Johnny thinks. But he has already broken two of his own rules in taking this job: Rule 1: Never get involved with personal relationships. Rule 2: Never get involved with gangs.