Victoria “V.I” Warshawski is a Chicago based private detective who agrees to babysit for her new boyfriend; then he is murdered. Being the detective type, she makes the murder her next case. In doing so she befriends the victim’s daughter, Kat, and together they set out to crack the case.

A space shuttle mission investigating Halley’s Comet brings back a malevolent race of space vampires who transform most of London’s population into zombies. The only survivor of the expedition and British authorities attempt to capture a mysterious but beautiful alien woman who appears responsible.