Captain Blacker was an MI5 agent and a character from The Man From MI.5. Carl sneaked aboard his ship while it was anchored in harbour on the French Riviera, where he was shot. Afterwards, Carl thoroughly searched his desk and eventually located secret papers. He then placed a limpet mine on the ship's hull and made his escape. Fellow MI5 agents Jimmy Bondson and Tidman both witnessed the explosion, and when Bondson dived down to the wreck, he discovered signs of foul play.
- The puppet used for Captain Blacker also appears in The Cham-Cham as Captain Savidge, and in Danger At Ocean Deep as Lieutenant Jensen.
- He appears to be a TV21 reader; the back page of #32 and the front page of #33 can clearly be seen as Carl is rifling through the cabinet drawer.