Nick Tate's absence from this episode is the result of Fred Freiberger's disinterest in rehiring him for Season Two until someone brought to his attention that Tate had been receiving more fan mail than any other actor, so he'd be missed. When Tate returned to the series for Season Two, he was told a story by one of the production staff of how his kids became disappointed to hear that Alan Carter wasn't included in the upcoming season (Tate himself thought it was insane that just about the entire first season's supporting cast had been excluded from this new season). Freiberger then decided to use the same story about re-hiring him due to the reaction of his own kids. Tate played along but knew Freiberger fabricated the story. During Season One, American interference with the show's production was considered an unwanted presence by the cast and crew, but they were forced to relent. So, although Tate tried to act civil with Freiberger, he didn't take any nonsense. It turned out that eight episodes had already been scripted before Tate rejoined the series, so Alan Carter had to be written in. However, after The Exiles (1976) had Carter in a small cameo role, Tate threatened to quit the series unless his character had a significant appearance in the scripts going forward. When Tate later found that The Taybor (1976) only had Carter in a five-second scene, he disappeared for two weeks, necessitating his character to be replaced by John Hug (Bill Fraser) in both "The Taybor" and the following episode produced ("Brian the Brain"). Tate pointed out that Freiberger could've had him sued for breach of contract, but no action was taken. After returning, the only absence Tate's character was given for the remainder of the season was during the "double-up" episodes (two shows filmed simultaneously). Years later, Tate was asked about his opinion of Freiberger; he answered, "We got along well enough, but I knew who he was from day one".
Marc Zuber (security lieutenant) had played a Main Mission operative (sans mustache) on Season 1's Black Sun (1975).
Near the episode's conclusion, there's a deleted scene right after Koenig tells Brian he has a message from Captain Michael, in which Koenig and Helena try to confuse Brian by contradicting each other over who will maintain Brian during their travels through space (known in the Star Trek universe as "talking a computer to death", as Koenig had done on Ring Around the Moon (1976)).
When Martin Landau picks up the mouse, he almost breaks character (stifling a laugh) as it almost leaps out of his grasp, ad-libbing "Easy, Maya".
The interior of the Swift was mostly made up of the interior set of the Voyager from Voyager's Return (1975).