 In this episode, the Mysterons attempt to destroy London by hi-jacking a transporter carrying an atomic device.Like the previous episode, "Winged Assassin", "Big Ben Strikes Again" was postponed during BBC Two's 2001 repeat run of "Captain Scarlet" due to similarities between its plot and the September 11 attacks.The Mysterons (voiced by Donald Gray) announce that they intend to destroy London.