Mike and Velda visit Joe, who tells them of a military project in Saigon involving the use of drugs to turn prisoners of war into friendly spies and how Captain Romero developed a technique for mind control.

While watching this session, Hammer hears the twins being attacked but is too late to prevent their deaths at the hands of a psychotic killer.

Chambers, again being secretly instructed by the CIA, tells Hammer that Kalecki supplied the gun that killed Jack and owned the apartment building where Kendricks lived.

Hammer captures Kalecki and forces him to drive back to the Northridge Clinic, where Romero has now set up a sequence of fortifications and death-traps.

Later, Hammer visits Dr Bennett at her home, bearing an expensively wrapped gift that turns out to be Jack's prosthetic arm.

According to screenwriter Larry Cohen, he was originally hired to direct but was fired after expressing his concerns to cast or crew over the producers running out of money.

[6] Cohen immediately starting shooting Q - The Winged Serpent in Manhattan, filming concurrently with Richard T. Heffron's completion of I, the Jury.

[7] In advance of its UK theatrical release that same year, on March 3, 1982, the BBFC classified the film as an X (its then-regular over-18 cinema category) after requiring some cuts that toned down the juxtaposition of sex and violence.

Included in these video cuts were an extended conversation between Hammer and the sexual surrogate twins, orgy scenes at Dr. Bennett's clinic that intercut orgasm with the violent torture of the twins by Kendricks (a psychopathic killer with a cut-throat razor), cuts to a scene where a woman has her throat slit in a Chinese restaurant and the complete removal of Hammer's high-speed cab ride through Manhattan, which had been closely intercut with the sadistic knife torture of Velda by Kendricks.

[4] Others felt that Cohen's CIA/Mafia back-story added a welcome sardonic quality in keeping with the spirit of Spillane and that graphic scenes of sex and gunplay were key to faithfully adapting the fevered narrative of the novel.

[4][10] The New York Times' Jennifer Dunning enjoyed Assante's casting and found the pulp film highly entertaining: Along the way there are spectacular chases and ingenious gore, including a water bed that oozes blood.

She's Mike Hammer's private secretary, and she is played by Laurene Landon, the tall blonde who was one of the wrestlers in Robert Aldrich's "All the Marbles."

[14] It was also released uncut in an upgraded special edition Blu-ray in the USA on November 8, 2016 by Kino Lorber, with a commentary track by film historian Nathaniel Thompson and Cohen biographer/filmmaker/documentarian Steve Mitchell[15]