Leonard Nimoy had become increasingly disenchanted with the quality of Star Trek (1966) during its final season, especially the way his character of Spock was being handled. Eager to find challenging new work, he accepted the role of Paris and was signed for eight shows at $7000 per show on a par with Peter Graves.
With the departure of Barbara Bain after season three due to a contract dispute, creator Bruce Geller composed a list of prospective actresses for this two-part season four opener. The list included Dina Merrill, Gena Rowlands, and Jessica Walter. Geller decided to select Lee Meriwether, a guest star in last season's "The Bunker". But Douglas Cramer, a Paramount executive, suggested to Geller that Dina Merrill be cast as she possessed star caliber. Geller countered that she was discussed, but Lee Meriwether was the preferred choice. In a bit of subterfuge, Cramer replied that producer Stanley Kallis said Dina Merrill was fine by him. But Geller later learned what Kallis really meant was that it was by all right by him if it was all right with Geller. For once, Geller had been conned IMF style.
The studio's Administration Building doubles as State Security Headquarters. It would appear on-screen frequently in future shows under a variety of guises.