A frightening journey into the unknown awaits when a mission to investigate Halley's Comet discovers an even stranger phenomenon: an alien spacecraft! Following a deadly confrontation, the aliens arrive on Earth, where their seductive leader begins a terrifying campaign to drain the lifeforce of everyone she encounters. And when the mission's sole survivor (Steve Railsback) sets out to destroy her, he comes face to face with the most charming - and horrifying - being he's ever known!