Answers from the Grave - Tapa blanda

Then: Once upon a time in south London, three young men without a future decide to invent their own. The Sixties are starting to swing and Jimmy, John and Billy want the clothes, the pills, the music and the women. Through drugs, protection and armed robbery, they get most of what they want. But then Billy changes sides and becomes a cop...and finds that his days are numbered.
Now: Billy's son, Mark, is working for John Jenner and waiting for the day when his father's killer gets out of prison. It's any time now and Mark is determined to be there when the doors swing open.