A mechanical brain is programmed to sabotage the government's secret lab while working on the first space station.
| Actor | Role |
|---|---|
 Richard EganDavid Sheppard | David Sheppard |
 Constance DowlingJoanna Merritt | Joanna Merritt |
 Herbert MarshallDr. Van Ness | Dr. Van Ness |
 John WengrafDr. Zeitman | Dr. Zeitman |
 Philip Van ZandtDr. Pierre Elzevir | Dr. Pierre Elzevir |
| VValerie VernonMme. Elzevir | Mme. Elzevir |
 Byron KaneDr. Carter | Dr. Carter |
| SStephen RobertsMaj. Howard | Maj. Howard |
 Michael FoxDr. Hubertus | Dr. Hubertus |
 Aline TowneDr. Kirby | Dr. Kirby |
 Marian RichmanHelen | Helen |
| JJean DeanMarna | Marna |
 William SchallertEngle | Engle |
 David AlpertDr. Peter Burden | Dr. Peter Burden |
| TTom DalySenator | Senator |