“The Trace McCloud Story.” From the Wagon Train series: Season 7, Episode 24 (250th of 284). First broadcast: 2 March 1964. Regular cast: John McIntire (Christopher Hale), Robert Fuller (Cooper Smith, credit only), Frank McGrath (Charlie Wooster), Terry Wilson (Bill Hawks), Denny [Scott] Miller (Duke Shannon), Michael Burns (Barnaby West). Guest cast: Larry Pennell, Audrey Dalton, John Lupton, Paul Newlan, Rachel Ames, Stanley Adams, James McCallion, Nora Marlowe, Harry Harvey. Writer: John McGreevey. Director: Virgil W. Vogel.

   Whenever a long-running TV series runs short of ideas, they sometimes depart from their usual genre (in this case, the Western) to borrow from other genres (in this instance, the mystery/whodunit).

   As Christopher Hale’s wagon train wends its way westward, they sometimes have to stop for replenishment in small towns along the trail. It so happens that in Bedrock, one of their stops, they get to enjoy a traveling magic show — which is abruptly terminated by a murder.

   Wagonmaster Hale learns then that a series of stranglings have occurred in Bedrock, and the local marshal doesn’t have a clue who’s doing them.

   Almost immediately a sizable percentage of the nervous citizens of the town, as well as the itinerant magician, join up with the wagon train. So does the marshal, who thinks the strangler might find the prospect of more potential victims attractive. While Hale welcomes the marshal’s presence, he knows his life just got a lot more complicated.

   The marshal’s suspicions seem to be confirmed when several more murders happen as the train moves on, with the strangler barely escaping detection each time.

   At this point, Chris Hale would be justified in wondering if there’ll be anybody left when they finally reach the end of the trail.

   This episode does a very good job of keeping us guessing by ingeniously shifting suspicion around among the characters; the story benefits by having an hour and half to play in, giving ample time to insert red herrings.

   The solution, admittedly far-fetched, does border on the implausible, but the fun, as in all thrillers, is getting there.