Star Trek was far from the only freshman series airing on Fridays in 1966. ABC had The Green Hornet & The Time Tunnel, and gave Milton Berle a shot at a primetime comeback. NBC, meanwhile, backed up Trek with T. H. E. Cat, a half-hour series about a circus performer-turned-cat-burglar-turned-bodyguard for hire.
Robert Loggia (ex-The Nine Lives of Elfego Baga) had the title role as Thomas Hewitt Edward Cat. In the opener, "To Kill a Priest", Cat is asked by his contact with the San Francisco PD (R. G. Armstrong) to protect a priest marked for murder (Jason Evers, ex-Combat!). Look close, and you'll see Sorrell Booke, 13 years before The Dukes of Hazzard made him famous, as one of the villains.
Posted in memory of Loggia, who passed away at 85.
Series creator Harry Julian Fink was also the genius who gave us another San Francisco maverick, one "Dirty" Harry Callahan. The jazzy score was composed by Lalo Schifirin (Mission: Impossible, Mannix), who would go on to score a few of Clint Eastwood's "Dirty Harry" movies.
So why did it fail? Airing too late at night might be the answer, since it was penciled in to air at 10 or 10:30 (ET). Then again, NBC didn't know what to do with Star Trek, either.