The aliens organize a series of armored car heists in order to finance the purchase of rubies for their new laser weapons. Meanwhile, Ironhorse is kidnapped by the vengeful husband of a woman Ironhorse had accidentally shot dead while battling an alien raid at a research installation.

The team set up in Chicago to investigate a spate of kidnappings but encounter resistance from the local police. Nevertheless they discover a secret cell of alien scientists, who are trying to create a designer drug which turns addicts into frenzied killers.