While on a bus to Portland for a sheriff's conference, Jessica and Sheriff Tupper get derailed by engine trouble. However, Sheriff Tupper's desire to make it for the banquet and the prize drawing quickly become the least of their worries when Jessica finds one of the passengers on the bus with a screwdriver in his neck. Jessica quickly deduces that the killer must be one of the other people on the bus, but sleuthing out which one will prove complex and tricky.
This episode contains examples of the following tropes:
- Brick Joke: Sheriff Tupper's hope that he can win the drawing for the TV comes up multiple times during the episode. Then, at the end, it turns out Jessica would have won it had she not been delayed.
- Confess to a Lesser Crime: Downplayed; when Sheriff Tupper confronts him with evidence that he sabotaged the bus so he could kill Mr. Stoner, Ben Gibbons tearfully confesses to stabbing him, but Jessica points out that for murder weapon to have been as bloodless as it was, Mr. Stoner had to have been dead already when stabbed. It turns out that Gibbons strangled Stoner in a rage beforehand. He stabbed him as a coverup and confessed to that when confronted, knowing the coroner would say Stoner had died of strangulation, not stabbing.
- Closed Circle: The riders can't leave because the bus won't start. The phone lines have also gone out during the storm, and they can't simply walk for it because of the storm outside.
- Everybody Did It: A downplayed variant; three people on the bus are guilty of something related to the crime, but two — Mrs. Radford and Captain Downing — were only guilty of trying to steal something from the dead man's effects. The person who actually killed him was the bus driver, Ben Gibbons.
- Retirony: A variant; Stoner had just gotten out of prison and was ready to start his life again when he was killed by the father of a teenager accidentally killed during a robbery attempt.
- Sympathetic Murderer: The victim is a convicted bank robber freshly released from prison. During the robbery he had killed a teenage girl, and when her father confronts him he insults her, driving the father to strangle him. Jessica admits she feels bad for the killer, but suggests that he could make a good case for temporary insanity.
- Tempting Fate: Stoner claimed nobody could do anything else to him for Miss Gibbons' death, as he had already served his sentence. Mr. Gibbons soon showed him there was something else he could do.