This is James Daly's second appearance in the show, his first was in the pilot, Beachhead (1967), as Alan Landers, David Vincent's business partner and friend.
This is Alfred Ryder's second appearance as an Invader "Leader." Although he is never given a name, Vincent calls him "Ryder" in this episode.
The license plate of the car the alien escapes in during the first act is: JK 8004 (Maryland).
The Maryland license plate on the front of the car driven by the alien reads JK:8004 with MARYLAND underneath the number in a smaller font is inaccurate. Nothing on the license plate is stamped into the metal plate. The thin blue border is missing as is the expiration date which should have been at the top of the plate just inside the border in the format of EXP. with 1 digit for the month, 2 digits for the day and the last 2 digits of the expiration year. Also the plate number is two letters and four numbers separated by a colon. They should have been separated by a hyphen.