Monk gets a visit from a woman named Linda Kloster, who knows her husband is planning to kill her and wants Monk to convict him for it after the fact. However, while Monk knows the culprit, obtaining enough evidence for a conviction may prove more difficult, as Linda's husband, chessmaster Patrick Kloster, seems to stay one step ahead of him the whole time.
This episode contains examples of the following tropes:
- Batman Gambit: Patrick Kloster poisons his wife with a "poison pawn" - a trap that is impossible for the victim to resist. In this case, this involves him discovering her secret stash of liquor, poisoning that, then counting on her to hide the bottle herself so he wouldn't have to.
- Framing the Guilty Party: Patrick Kloster has practically admitted to killing his own wife, and the alleged poison matched that which could be extracted from oleander flowers in Patrick's garden. Unable to find adequate evidence and driven to his wits' end, Monk steals some of the flowers, extracts the poison, breaks into Patrick's house to leave it in plain sight on a shelf, and only gets caught when he went back to retrieve the planted vial after his conscience got the better of him, as Patrick had apparently anticipated to try this move.
- Freeze-Frame Bonus: When Natalie opens the second of Patrick Kloster's books, you will notice on the left page a list of all of Patrick's other books, which include Ultimate Chess Tactics, The War Of Chess, Winning Endgame Play, Ninja Chess, Unbeatable Chess Strategies, Play Chess and Conquer, Grandmaster Chess Secrets, Five Moves Ahead, and Power Chess Strategy.
- GPS Evidence: Played with. Monk realizes that one of the flowers in Patrick Kloster's yard is poisonous oleander, and takes it to the Captain as his primary evidence... where he is immediately shot down because it's way too common to be admissible as evidence. However, when Monk and Stottlemeyer take a petition to have Patrick's first wife's body exhumed after they realize that her death and Linda Kloster's death are both similar in nature, the judge notes that among other things, Patrick had been growing oleander plants in his garden around the time of his first wife's death as well.
- Reverse Whodunnit: We know that Patrick Kloster is the culprit from the very beginning, due to his wife visiting Monk to inform him right before she herself gets killed. So Monk spends the plot trying to find how to nail Patrick.
- Tampering with Food and Drink
- Patrick killed Linda by spiking her secret liquor bottle with oleander.
- While Natalie and Monk are staking out Patrick's house, he offers them lemonade. Natalie starts to drink hers, until Monk muses out loud that they could probably nail Patrick if he poisoned Natalie's drink. She immediately spits it out.