• 
  Joi Lansing
• 
  Richard Carlson

   Herbert A. Philbrick (115 episodes, 1953-1956)
• 
  John Zaremba

   Special Agent Jerry Dressler (67 episodes, 1953-1956)
• 
  Ed Hinton

  Special Agent Hal Henderson
• 
  John Beradino

  Special Agent Steve Daniels
• 
  Charles Maxwell

  Special Agent Joe Carey
• 
  Patricia Morrow

  Constance Philbrick
• 
  Charlotte Lawrence

  Carol - Philbrick's Secretary

• 
  Tom McKee

  Comrade Brisson Laylock
• 
  William Hudson

  Special Agent Mike Andrews
• 
  Alan Reynolds

  Comrade Jack Blake
• 
  Ken Duncan Jr.

  Comrade X
• 
  Merritt Stone

  Comrade Mitch
• 
  John Frank

  Comrade Lothar
• 
  Mitchell Kowall

  Comrade Joe Burton

• 
  Charles Victor

  Comrade Dan Burt
• 
  Walden Boyle

  Special Agent Adams
• 
  Jeanne Cooper

  Comrade Sally
• 
  Virginia Stefan

  Eva Philbrick
• 
  Jo Gilbert

  Comrade Eileen
• 
  Norman Rainey

  Dad Philbrick
• 
  Jean Bates

  Comrade Joan
• 
  Lester Sharpe

  Comrade John Bryson