'The Robot Freighter Mystery' by Alan Fennell

Having sabotaged a space freighter, two unscrupulous pirates known as the Biggs Brothers pose as a legitimate salvage company, loot the ship of its cargo and then blow it up; the two pirates then return to Earth and attempt to sell Commander Zero his own shipment. However, Zero is suspicious, and he instructs Fireball XL5 to escort the next freighter; but the brothers have already planted a bomb aboard the freighter, and, after distracting the crew of XL5 with a fake distress call, they ‘salvage’ the ship. When Steve Zodiac realises what has happened, he hatches a plan of his own…

Paul Maxwell (Colonel Steve Zodiac / Joe Briggs), Sylvia Anderson (Doctor Venus), David Graham (Professor Matt Matic / Lieutenant 90 / Slim Briggs / Emergency Call Tape), John Bluthal (Commander Zero / Jock Campbell / Edmundo), Gerry Anderson (Robert the Robot)

Directed by David Elliott
Produced by Gerry Anderson
Associate Producer Reg Hill

TX (UK - ITV):
23rd September 1963

Notes:
*Featuring Colonel Steve Zodiac, Venus, Professor Matt Matic, Commander Zero, Lieutenant 90 and Robert the Robot