The Cheif, Max and 99 journey to London in a fog-filled episode. The Chief is there to discover a KAOS leak in British CONTROL, while Max is to take the place of The Scar, a U.S. safecracker. The Scar is being recruited by the Scorpion Gang in a bid to rob the royal jewels. Under the Umbrella of Silence, British CONTROL reveals that not only will Max need to capture the Scorpion Gang, but he must discover the identity of X, the real leader of the gang. Max helps the gang rob the jewels and discovers that all is not what it seems in British CONTROL.

Danny Thomas has a cameo in this episode as a native Londoner asked for directions. To honor him, Don Adams does a beautiful spit take later in the episode.