Space agency director Nancy MacDonald gets a lesson in the meaning of time and distance with an unexpected signal from astronaut Christopher Lindy. Lindy, the man MacDonald once loved, disappeared on a routine space mission 20 years ago. Oblivious to the time that has passed, Lindy must deal with his present situation; being alone on an unknown planet. MacDonald turns to her husband, marine biologist Greg Tilman, to help Lindy survive attacks by an alien lifeform while she and her staff look for a way to save Lindy before the window of opportunity to save him once again disappears.