This is the only episode that does not show Moonbase or any SHADO equipment.
While this was the twentieth episode broadcast, it was the twelfth to be filmed.
The script was originally titled "Shoot to Kill". Two scenes were deleted from the script (presumably unfilmed): the destruction of a UFO at the episode's start; and Straker's and Freeman's attempt at gaining information by threatening to douse surveillance device manufacturer Singleton (Tutte Lemkow) with a petroleum solvent and setting him on fire. The opening scene showing Foster's verdict in court was not in the script.
The location shot of the IAC headquarters is from "Conflict" and the shot of Foster's apartment is from "Exposed".
At 35:20; the hubcaps on the front wheels of the bronze SHADO car differ from the hubcaps on the rear wheels.