In the near future, a space station dubbed Earth II is built for the purpose of scientific research and world peace. However, that peace is shattered when the Chinese send up a nuclear bomb that is orbiting just a few miles away from the station. Can the crew disarm the bomb before it detonates, not only destroying the station but setting off World War III?
| Actor | Role |
|---|---|
 Gary LockwoodDavid Seville | David Seville |
 Scott HylandsJim Capa | Jim Capa |
 Hari RhodesDr. Loren Huxley | Dr. Loren Huxley |
 Anthony FranciosaFrank Karger | Frank Karger |
 Mariette HartleyLisa Karger | Lisa Karger |
 Gary MerrillWalter Dietrich | Walter Dietrich |
 Inga SwensonIlyana Kovalefskii | Ilyana Kovalefskii |
 Edward BellAnton Kovalefskii | Anton Kovalefskii |
 Lew AyresPresident Charles Carter Durant | President Charles Carter Durant |
| BBrian DeweyMatt Karger | Matt Karger |
| DDiana WebsterHannah Young | Hannah Young |
| BBart BurnsSteiner | Steiner |
 John CarterHazlitt | Hazlitt |
| HHerbert NelsonChairman | Chairman |
| SSerge TschernischRussian | Russian |
| VVince CannonTechnician | Technician |
| DDavid SachsSurgeon | Surgeon |
 Robert F. HoyWest | West |
 James HongChinese Military Official | Chinese Military Official |
 Soon-Tek OhChinese Diplomat | Chinese Diplomat |
 Stack PierceMission Control Worker | Mission Control Worker |