A parasitic alien soul is injected into the body of Melanie Stryder. Instead of carrying out her race's mission of taking over the Earth, "Wanda" (as she comes to be called) forms a bond with her host and sets out to aid other free humans.
A beautiful woman from the city, Jennifer Hills, rents an isolated cabin in the country to write her latest novel. Soon, a group of local lowlifes subject her to a nightmare of degradation, rape, and violence.
When their bus is crippled on the side of a deserted road, a team of high school athletes discover an opponent they cannot defeat – and may not survive.