Revolves around a British military contractor Lex Walker who is told his daughter has died. When he arrives in Los Angeles and discovers the body is not hers, he begins an investigation.

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.