Perry and Della have a conversation about her superstition regarding travel, which was never discussed in the earlier series. When she and Perry meet up in the courthouse's coat room, she complains about having difficulty getting a train to Denver. After Perry chides her about her "silly superstition," she scoffs at him, saying she flies when she has to, but adds "only not on Friday."
Exteriors of the "Briarcliff Hotel" are actually the Broadmoor in Colorado Springs.
Five of the actors in this film made guest appearances in various versions of "Star Trek", Percy Rodriguez in the original series, Dwight Schultz and David Ogden Stiers in "ST The Next Generation", Matthew Faison and Leigh Taylor-Young in "ST Deep Space 9".