Colonel McCauley returns from Asteroid 78-1. The mission was cut short by the failure of his suit oxygen supply. He is insistent that just before he passed out he saw fossil evidence of life on the asteroid. Unconnected with this, Air Force medical staff have recommended his prolonged series of missions requires a 60-day 'grounding' to recover from stress. Will McCauley be able to lead the return mission to the asteroid if its unpredictable orbit permits another rendezvous? (thetvdb.com)