Detective Edward Delaney (Sinatra) is an NYPD homicide cop weeks away from retirement. He picks up what promises to be his final case — a man was murdered on the sidewalk by an unknown assailant, who struck him in the head with an unknown weapon — with nothing more to go on than that the killer used a weapon with a round, tapered end.
Delaney consults an expert in medieval weaponry, who ascertains that the murder weapon must have been a modern-day tool. Doing some research on his own, the weapons expert discovers that the killer used an ice axe. Meanwhile, Delaney learns about another deadly attack committed not all that far away, in which the victim suffered similar wounds to the skull. After looking at past crime reports, he determines that a serial killer is stalking Manhattan.
While all this is happening, Delaney's wife Barbara (Dunaway) is dying. She went into the hospital for kidney stones, but doctors found her kidney badly diseased and damaged and had to remove it, and she is growing steadily weaker as infection rages in her body.
Frank Sinatra's last starring role, and in fact his next-to-last film appearance (his last appearance was a cameo in 1984's Cannonball Run II). The supporting cast includes James Whitmore, David Dukes, Brenda Vaccaro, Martin Gabel, and Anthony Zerbe. A young Bruce Willis, in his film debut, appears as an uncredited extra.
- Badass Longcoat: The murderer stalks the streets in a long black coat, with deep pockets that he uses to hide his ice axe.
- Bittersweet Ending: Edward manages to kill the serial killer and end his rampage, but Barbara dies as Edward reads to her from her favorite old children's story book.
- Brandishment Bluff: One suspect catches Delaney in his apartment, whereupon he sticks a gun in Delaney's back and demands ID. Delaney complies, only to turn around and find the man is in a wheelchair and he was actually jabbing Delaney in the back with his cane.
- Chalk Outline: You wouldn't think the NYPD would draw a chalk outline on the sidewalk, but they did.
- Da Chief: Capt. Broughton, who straight up tells Delaney that he doesn't care about any crimes not committed in his precinct, even serial killers. He orders Delaney to stop his investigation but Delaney ignores him.
- Did I Mention It's Christmas?: It's Christmas season, with trees and carolers, but that has nothing to do with the story other than to provide an ironic counterpoint to the pursuit of a crazed serial killer.
- Gross-Up Close-Up: Part of the opening montage is a series of gross close-ups of Barbara getting her kidney removed. Extreme closeups of a scalpel slicing into flesh.
- ISO-Standard Urban Groceries: Edward decides to mix it up by bringing home a bag of groceries that has a loaf of Wonder Bread sticking out, rather than the standard French bread.
- Powerful Pick: Delaney eventually discovers that the murder weapon is a mountain climber's ice axe. This proves to be his break in the case, as he finds the sporting goods store that sold the ice axe, and is able to trace through the store's contact list until he finds the killer.
- Serial Killer: A very messed-up guy who goes around Manhattan whacking people on the top of the head with an ice axe.
- Shower of Angst: From a deranged psycho, as Daniel Blank the serial killer curls up in a bottom of his shower weeping, after he went out looking for a victim only to meet Edward and lose a stare-down contest.
- The Unfettered: After Blank comes out of his psychotic episode he taunts Edward, pointing out that Edward broke into his apartment and has no evidence, and that he (Blank) has high-powered lawyers and powerful friends and will get away with everything. Edward responds by shooting Blank in the head.
- Verbal Irony: Blank, calling the police, saying "I'm in no physical danger"...while Edward is standing behind him pointing a gun at his head. Edward then kills him.