"[voice-over] If man perishes from the face of the Earth, due to the effects of hydrogen bombing, it is possible that the next ruler of our planet may be The H-Man."

"Molecular Man Terrorizes the World!"

"Anthony Ireland — General Hayes"

"Hugh Moxey — Colonel Alfred Daniels"

"Ken Uehara — Dr. Kawano"

"David Horne — Minister"

"Eva Bartok — Dr. Lisa Frank"

"Alan Wheatley — Dr. Smith"

"Philip Leaver — Professor Koepler"

"Howard Duff — Dr. Stephen Mitchell"

"Edith Saville — Lady Grant"

"Space is a cold place to die!"

"Michael Medwin — Dr. Toby Andrews"

"The screen's first story of SPACE ISLANDS in the sky!"

"Andrew Osborn — Dr. Philip Crenshaw"

"Jennifer Dearman — Lena as a child"

"Stephen Murray — Bill Leggat"

"John Van Eyssen — Robin Grant"

"Glyn Dearman — Bill as a child"

"Kynaston Reeves — Lord Grant"

"Cecile Chevreau — Vanessa Mitchell"

"Percy Marmont — Sir Walter"

"John Stuart — Solicitor"

"Barbara Payton — Lena Maitland/Helen"

"An empty mind... and a new beginning!"

"She lived two amazing lives under his spell!"

"James Hayter — Dr. Harvey"

"Kumi Mizuno — Takiko Nomura"

"Takashi Shimura — Dr. Kensuke Sonoda"

"Sean Barrett — Robin as a child"

"Ed Wolff — The Robot"

"Hugh Huntley — Perkins, Dr. Mallory's lab assistant"

"Dora Clement — Ann Zorka"

"Anthony Averill — Rankin, a foreign spy"

"12 SPINE-SHIVERING ACTION THUNDERBOLTS! Sinister scientists...foreign spies...federal agents...and a pretty girl...crashing through amazing adventures!"

"CRASHING...SMASHING...DASHING DYNAMITE! 12 spine-shivering chapters of thunderbolt action and amazing adventure!"

"A BLAZE OF DYNAMITE ACTION! Crashing...smashing...dashing through 12 spine-shivering chapters!"

"[after surviving a car crash, Zorka notices the hitch hiker they picked up, who looks like him, is dead.] How fortunate, this will simplify everything!"

"George Rigaud — a professor"

"Barta Barri — a professor"

"Bela Lugosi — Dr. Alex Zorka"

"Ángel Álvarez — a professor"

"Emiliano Redondo — Prof. Kristoff"

"Jack Taylor — Olsen"

"Lone Fleming — Molly"

"Ricardo Palacios — a train ticket collector"