In the summer of 1976, one of the hottest on record, a young man's body was found in a ditch on a lonely Leicestershire road. At first, it looked like a hit-and-run. It wasn’t. 25-year-old plumber Gary Toms had been in a relationship with a married woman named Marlene Evans. Her estranged husband, Harold Evans, had spent months watching the relationship develop, attending court for breach of the peace, attempting suicide, and quietly acquiring a pistol. Was this a man pushed beyond breaking point, or a calculated, premeditated murder dressed up as provocation?…