On a cold dark December day in 2015, a tall grey haired man entered a London train station, bought a return ticket to Manchester and never came back. The following day his body was found on Saddleworth Moor, near Oldham. He was poorly dressed for the weather and carried few clues to identify him - no phone, no wallet, no passport or driving licence. For 12 months his identity remained a mystery. With exclusive access to the year long investigation by detectives from Greater Manchester Police, Mystery of the Man on the Moor tells the remarkable story of their painstaking work to identify him and to understand his lonely death. The film features previously unseen footage of the key moments of discovery as well as moving interviews with the man's family and former girlfriend who, despite extensive media coverage, both at home and abroad, had no idea he was missing.