A gruesome discovery sets the tone for a chilling investigation when a severed human arm is found floating in the Hudson River. Detective Lefransky, portrayed by Randy Jurgensen of the New York Police Department, promptly commands forensic scientist Dr. Rifkin, played by Barton Heyman, to connect this dismembered limb to a torso that had been uncovered prior.
Later that evening, in a bustling gay neighborhood in Manhattan, patrolman DiSimone, portrayed by Joe Spinell, alongside his partner, Desher, engages in a disturbing encounter when they forcibly detain two transvestite prostitutes, subjecting them to sexual harassment while they are bound in their police car. Nearby, a mysterious man characterized by his sunglasses and a sinister black leather jacket steps into a gay nightclub buzzing with men dancing, loving, and indulging in public displays of sadomasochism. In an unsettling turn, a patron named Loren Lukas approaches this man, and after some interaction, they retreat to a room at the St. James Hotel. There, under the cover of a dark and unsettling atmosphere, the man ties Lukas's hands and feet, and eerily sings, "I'm here, you're here, we're here," before committing a heinous act of murder, poignantly asserting, "you made me do that."
In the sterile environment of the forensics lab, Dr. Rifkin examines Lukas’s lifeless body and astounds Captain Edelson, played by Paul Sorvino, with grim news about the killer’s DNA redundancy—an indication of sterility due to the absence of sperm in the found ejaculate. As the investigation unfolds, they question DaVinci, a transvestite played by Gene Davis, who reveals the traumatic truth of being coerced into a sexual act by the aggressive patrolman DiSimone. Despite DaVinci's harrowing tale, Edelson displays skepticism, fueling a tension that lingers over the inquiry.
The plot thickens as Steve Burns, enacted by the remarkable Al Pacino, a youthful and ambitious officer, enters the scene. He is ordered by Captain Edelson to go undercover, posing as a homosexual to delve deeper into the murders of Lukas and a renowned gay college professor, Paul Vincent. As he reports to Edelson's office, he initiates the important brief about these vengeful killings, pushing himself into a covert operation that leads to unforeseen dangers.
In a deeply personal moment, Steve confesses to his girlfriend, Nancy, played by Karen Allen, that he has to undertake this potentially perilous assignment that will inevitably distance him from her, referring to it as his "deep undercover" work. During his infiltration into a polarized society, he adopts the alias "John Forbes" and mingles among the community, hitting the streets of the West Village where he befriends a neighbor, Ted Bailey, portrayed by Don Scardino. Their innocent lunch talk quickly leads into the chilling underbelly of the neighborhood’s dark happenings.
As the depths of the investigation reveal more sinister encounters, Steve witnesses the gruesome aftermath as the killer finds another victim, Eric Rossman, in a park and brutally takes his life, taunting him with songs echoing his earlier crimes. After a series of events that tug at his emotional stability while concurrently testing his dedication to the case, Steve experiences troubling dreams and a troubling disconnection from Nancy. They share moments of passion even as Steve wrestles the ghosts of his undercover life.
A tense series of criminal events follows—the fashion designer Martino Perry, who meets a gruesome fate, underlining the urgency for the police to resolve these murders before an important political event. Steve’s constant plunge into the nightlife and sordid activities leads him to discover connections between the victims and potential suspects. At the home of the killer, Stuart Richards, tensions escalate as Steve's stakeout threatens to flicker into violence, culminating in an arrest made under the guise of deception.
With dark motivations and a descent into madness revealed, Stuart Richards’s reveal as the killer adds layers to the chilling narrative. The unsettling finale weaves Steve back into a world he sought to leave behind when he decides to return to Nancy, who unknowingly picks up his sinister artifacts associated with the killer—a twist that leaves viewers unsettlingly aware of the overlap between his life and that of the murderer.
In the tense confrontation between Steve and Richards, the door closes on a story that reflects on the complexities of identity, the brutality hidden beneath societal norms, and a haunting reminder that some masks are harder to remove than others.
