Matlock witnesses a robbery at a convenience store, but when things start happening that make him look like he's losing it, including messing with his papers, sending him to the wrong parties, and submitting phony pictures of his hind end to the papers, Matlock begins to realise that someone is trying to set him up. He, Cliff and Conrad begin to go through some of his old cases, trying to figure out which recently released killer is out to get him, but everyone they think of seems to have an alibi.