The Z-Bomb was a doomsday weapon which, if activated, would explode with a force strong enough to split an Earth-sized planet in half. By December 1986, two or three were placed at strategic positions around the Earth. One of them was in the hands of the International Space Command and their secretary general had the authority to order it used. To prevent the unauthorised use of a Z-Bomb, the station holding the bomb must gain clearance from Geneva. This particular Z-bomb was located at Snowcap base in Antarctica.