Linda Merrick (Barbara Rush) is a mess. She's been treated for a drug problem, she cheats on her cold and distant husband and she just witnessed her lover kill someone. Clearly, she's not having a good day. In desperation, she goes to the same sanitarium where she was treated for her addiction and suddenly she finds herself being held prisoner! This is because she told them about the killing and the scumbags at this place are going to shake her down for a ton of money. Clearly these folks have never heard of the Hippocratic Oath! In the meantime, the boyfriend wants to find her...possibly to get rid of the one witness he had to the killing.
Linda's husband (Russell Johnson) feels responsible for her problems and admits to Cannon that he's been a crappy husband. He pays Cannon to go in search of Linda and get her before things get even worse.
This episode seems a bit more 'normal' than many "Cannon" shows. In other words, the problem and resolution seem like something a private eye might actually do...compared to many of the more fanciful episodes they made.