A space shuttle crew return to Earth, bringing alien "seeds" with them. These begin to grow into alien life-forms, needing hosts to complete their evolution... When their number reach the Threshold amount, they will be an unstoppable swarm, so it's up to two scientists to stop them beofre it's too late. Written by
Did You Know?
Closeup shots at the space shuttle launching at the beginning show the fictional orbiter Oklahoma. The longer distance shot immediately after launch is the real orbiter Discovery, and the shot immediately before booster separation is the real orbiter Columbia. See more