Tango one

In different parts of London, three recruits prepare for their first day at the Metropolitan police's training centre at Hendon. All three have secrets in their past they are keen to put behind them. But the Met has other plans for them. They are to join a team of undercover detectives, a secret unit involved in the long-term penetration of criminals gangs. And their target is one of the world's biggest drug dealers: Don Donovan alias "Tango One".