This episode starts with West visiting a hotel to meet a contact only in the dark hotel room he is nearly choked to death by the man who just killed his contact. The contact utters as his dying words "Enzo, silver", at least that is what West hears.
Then West joins up with two covered wagons heading for Denver, Colorado with a strong man, a midget(CoCo), a gambler, a casino owner, 4 women, and Jonathan Ashley Kingston (Artemus) aboard. The driver is a well known character actor from films & television & is there too.
Along the trail to Denver, a couple of folks are murdered. West & Artie are sure that Enzo, the famous European killer, is aboard the wagons & desperately try to find him before they arrive in Denver. Failing that, the plot thickens when they arrive in Denver.
Interesting that Ross Martin would use the same character name he has here in his disguise as the killer in an upcoming Columbo episode. This episode runs short even though it gets a lot of plot done in 50 minutes. When everything is wrapped up, there is a short comedy blackout with West & Artemus riding on the train playing chess. This episode does try to surprise the viewer & if you have not already seen it, the final revealing of who Enzo is might surprise you.