This episode gives a clue about the origins of the 'Liberator', the space ship with superior technology that Blake and his crew are allowed to take over: apparently it is a space ship abandoned during a space battle between two powers that are unknown to the crew of the Federation ship London. It is not clear, however, why a ship that appears to be undamaged has been abandoned by its original crew.
This was the first episode to be filmed but the second in broadcast order.
Vila is shown to perform magic tricks, something he would do again in The Keeper (1979) and Sarcophagus (1980).
This episode was edited for all of its video releases. Approximately four seconds were cut where Avon gives a guard a double-handed blow at each side of his head, something the BBFC said would require an "18" certificate. Ironically, when the first four episodes were originally released onto video, edited together as one long story "The Beginning", the offending scene was left intact. The first unedited release for the episode occurred on DVD in February 2004, where it was given a PG certificate. The episode length when edited runs to 52'03 minutes.