"Hitch-Hike Poker" originally aired September 16, 1948 with Gregory Peck as the leading man. Peck plays a war veteran out hitchhiking; a motorist who picks him up introduces him to a way to play games of poker by using the license plates of passing cars. It's innocent enough until the motorist tries to murder his passenger! You may download the episode from archive.org here.
What makes "Hitch-Hike Poker" stick in my memory is the titular game itself; I come from a family which would spend a lot of time on the highways and my siblings and I would have to either concoct our own amusements or stare vacantly out of the windows. We did play games with license plates, although being the upright kids we were, we never thought to turn it into a game of poker. Lucky thing too, or it would have been an easy step for me to start gambling matchsticks. What then, bottlecaps?
Suspense repeated this script on January 25, 1959 as "Four of a Kind" with Elliott Reid in Peck's role. Although this other version truncates the story a little, it's also very good - in fact, I like some of Reid's line readings much more than Peck's. You can try it out from archive.org here.
Tomorrow: "There was something about him, like I was watching myself. Then I realized there was something - someone in the darkness behind him!"