In the distant future, the B.E.D.A. Corporation, a company involved in the development of electronic equipment and military weapons, is actually a front operated by a race of alien beings who have been living on the Earth for centuries in secrecy. The aliens have developed a substance named "Gel", which was initially intended to be used as food for their species, but also functions as an addictive substance to humans that results in terrible side-effects and is now being sold as an illegal drug within the underworld.
The player takes the role of Detective Hart, a member of the Vice unit who is assigned to investigate the B.E.D.A. Corporation following the disappearance of his partner Reese during a previous case. During his mission, Hart is assisted by his lover and fellow Vice agent Christy, and Sophia, an acquaintance of the two.