Jack in Clink

Jack is out on Wanstead Flats, late at night, with his telescope. There's a cry for help, some way off. He rushes over to assist, to find, to his amazement, the body of his employer. Jack phones the police. They'll sort it out, surely. But when they come, the cops confiscate his van, his telescope, and arrest him for murder. How will he get off? Who is fitting him up? Why? In prison, awaiting trial, evidence piling up against him, Jack needs help or he'll be facing twenty years in the clink.