Over the last two nights I watched a couple episodes of
The Outer Limits from 1964, "I, Robot" with Leonard Nimoy and "Cold Hands, Warm Heart" with William Shatner. They aired on September 26th and November 14th respectively.
Nimoy plays a reporter who is covering a sentient robot accused of murdering its creator. He also helps get an attorney to defend the robot in the subsequent hearing. John Hoyt appears as a witness at the hearing, so he worked with Nimoy a couple of times that year. When the episode was remade in the 90s, Nimoy played the lawyer. (Nimoy's son Adam directed the remake.)
In Shatner's episode, he plays an astronaut who's just returned from a mission to Venus and begins feeling cold all the time. Malachi Throne plays Shatner's doctor who's at a loss to explain what's happening to him.
Star Trek III's James B. Sikking plays a botanist, and Lawrence Montaigne appears as a construction worker (I missed Montaigne in the episode, but he is credited.) At one point Shatner's character gives a speech to his wife about traveling to new worlds to find new life, and his next planned mission is to Mars as a part of "Project Vulcan."
It made me realize how common it must've been for jobbing actors in the 60s to constantly run into each other on different jobs as they went from one series to another. And of course on November 24th's episode of
The Man From U.N.C.L.E., Shatner and Nimoy would work together for the first time in "The Project Strigas Affair."