Trivia: When the Captain Scarlet series was sold to TV broadcasters, ITC (who had backed and then marketed the series) issued a "recommended broadcast order". This was not always the same order as the episodes had been made. Episodes 1 to 4 were made and broadcast "in sequence", but from episode 5 this no longer applied. Episode 11 ("Avalanche") was the 5th to be broadcast, swapping places with the episode "Point 783" which was the 5th to be made, but the 11th to be broadcast.
Trivia: Bob Lynn, the TVR-17 disc jockey, is named after Robert Lynn, the director of this episode.
Trivia: This episode features flashback footage from "Big Ben Strikes Again", "Crater 101", "The Trap" and only eleven minutes of new material. The flashback to "Crater 101" also features a flashback of its own.
Trivia: Captain Scarlet's voice and face were based on the actor Cary Grant.
