The noir genre evokes images of grim private eyes, the trenchcoated/fedora hatted Humphrey Bogart archetype of The Maltese Falcon. Plot twists, the seedy side of the tracks, and so forth. Alfred Hitchcock and company mined the genre through multiple movies, but "Kiss Me Deadly" took it to another level.
HERE BE SPOILERS (some events changed/out of order to not completely spoil)
As written by the screenwriter who loosely adapted Mickey Spillane's book to the screen, Mike Hammer is not a paladin with a pistol, but a scumbag. Spillane was livid to see this interpretation of his character, but it's truth in fiction. Private eyes don't typically get hired by rich socialites to lucrative expense account contracts to solve murders the family would rather keep hush-hush. They're usually assigned to tail cheating husbands or wives, taking photos of sex in hotel rooms and combing through trash for evidence of infidelity. The police don't see Hammer as a John Shaft style fellow warrior for justice - they note that he's not even happy enough to collect money by being a professional peeping Tom, extorting both sides of the relationship using his own secretary as bait. He's not in a grungey office dimly lit through half-closed blinds, curls of cigarette smoke caught by the single bulb burning over a worn wooden desk - he drives a flash car and has a really nice well lit pad in what's presumably a good part of Los Angeles. He's making good money - only he's soulless.
Things change for Mike Hammer when a desperate hitch hiker jumps into the road at the risk of her own life, causing Hammer to go off the road. He grudgingly lets her into his car, having decided since he's stopped, he might as well take her further up the road. She describes him as a self-centered man with a hard body but no heart, and things get weirder when it's obvious people are looking for her: a police roadblock tries to find a missing woman from a local asylum. Thinking quickly, Hammer tells a ruse about her being his wife, and they wave him on. They stop at a gas station because the steering isn't right. She goes to the washroom and asks the attendant to mail a letter for her. Meanwhile they find out that there's debris from the side of the road stuck in the wheel, which they remove.
Resuming their trip, she promises to burden him only to the next bus station. If they make it, he can and should forget about her forever. But a car full of hoods runs them off the road. Her screaming in terror fades to her screaming in agony as we see her legs (and mercifully, only them) kicking away dangling from a table in an unknown location - as two men are clearly doing something to her. Something involving a set of pliers, which when one man straightens his arm beside him drop into view: clearly censored as being bloodless, but the scene only just made it into the film. The other man claims that she hasn't passed out from the ministrations of the first, but that he has managed to kill her without getting the info they need.
They decide to place her dead body and Hammer, who is vaguely conscious enough to make out the main speaker's distinctive shoes, into his car and send it down a ravine.
Hammer wakes up in the hospital to find out that his car is totalled beyond repair and he is lucky to be alive. The police, however, want to know as much as they can about the girl in question. Unfortunately, he doesn't know enough about her to tell them much, even if he would.
What follows is him trying to get to the bottom of the mystery: he finds out who she was and goes to her apartment, which is being vacated of her belongings when he arrives. He comes away from it with two things: a book of poetry, and the location of her roommate, thanks to a tip from the porter. From then, things get increasingly dark. First a hood tries to stab Hammer in the kidneys while he's out chasing a lead. He crashes a garden party of a well-connected hoodlum trying to find out more, and knocks out one and scares the other hitmen when they're sent by the boss to stop him. The other side have been learning more about him. They gift him a brand new car (leaving messages on his phone to contact him) with the understanding that if he accepts the replacement car, he forgets all about the case. Hammer's no fool and stops his mechanic from starting it, avoiding losing his close friend to the dynamite stashed in the engine compartment, wired to the starter. They find a second bomb under the car, wired to the spedometer to go off when it reaches a certain speed (which could only happen in the countryside given city speed limits... meaning they meant to end his life where there'd be no witnesses). He is, however, ambushed in his office and dragged to a beach house and injected with sodium pentothal to try to find out what he knows. He says nothing of any value, but manages to slip a hand free. He kills the thug, and calls the other two in. One follows and dies screaming offscreen. The second rushes in in time to hear Hammer racing away in his car.
He decides that whatever this thing is, it's valuable enough to kill for, meaning it's valuable enough for him to find and fence, no matter what it is. Then, when his best friend is killed (he sends the mechanic off in search of who might have planted the bombs in the car - a hitman drops a car on him by releasing the car lift with him underneath it) and his secretary is kidnapped it goes from revenge to concern for her safety.
We never find out what it is, it's a small, nondescript box that glows inside when opened. Hammer doesn't open it fully as it burns his wrist when he tries. He finds out from the gas station attendant she mailed the letter to a man named Mike. He speeds back to his office to read it. So have others. It simply says: "remember me". He's eventually worked out that "Remember me" is a reference to the sonnet in the book he found, which leads him to the coroner to see if she swallowed something when they stopped at the gas station. She did, but the coroner wants significantly more money than Hammer bribes him with. When Hammer breaks his fingers in a desk drawer, the item is handed over. It's a key to a locker at a health club, where the fatal object is located.
He leaves it where it is, assuming that since he's the only one to have found it, it's safe where it is. He's intercepted by the police again, who inform him that they can't tell him what it is, but it involves the Manhattan Project, and that it is of no value to anyone he's associated with. It would, however, be incredibly valuable to.... certain people. Certain people who have no problems using something like that. Also, the woman he's been hanging around with and protecting for the past week is not the dead woman's roommate - that woman was pulled from the harbor a week ago. God only knows who this woman Hammer's been palling around with is, but her sudden disappearance after Hammer found the box now makes a horrible, horrible sense. Basically, Hammer's way in over his head: he's nothing more than a thug with a PI badge. Hammer hands over the key, with absolutely no other response than shell shock. "I didn't know..." he says weakly. "If you had, would you have done the right thing?" sneers the officer, walking away with the key.
The police are too late: the receptionist at the health club has been murdered and the locker pried open, the contents long gone.
Desperate to at least salvage the life of his remaining friend, Hammer goes to see an art dealer connected with the case, who tries to commit suicide with sleeping pills when he hears Hammer break in. Hammer grabs the pill bottle to see what he can do about it, and sees the name of a doctor whose name he has heard before in connection with the case. Now he knows who tried to lock up the hitch-hiking woman before and hide her away in an insane asylum.
According to his secretary, the doctor's away at his beach house. Hammer immediately knows where he was taken by the two hoods earlier, and races out there. Meanwhile the woman who's been posing as the dead woman's roommate asks the doctor what they've been looking for. He won't tell her, and not realizing the import, she gets angry. She pulls a gun on him and demands half. When he explains it can't be halved or divided, it doesn't work that way she shoots him out of spite. Realizing he's dying the doctor desperately pleads with her not to open it, but to take it to a certain person... but dies before finishing his sentence.
Hammer bursts in and tries to reason with the woman, looking for the secretary, and she shoots him. She then opens the box, screaming in agony as she catches fire. Whatever's inside begins to melt down and melt down in a VERY BAD WAY, and Hammer crawls to his feet, finding the secretary just as the house explodes. A later print, restoring the original ending - has them making it out of the house but turning back, half in the ocean, as the thing melts down completely and torches the house, STILL leaving their fate ambiguous.
According to the scriptwriter, Spillane had WORDS for him when the two met: and not kind ones at that. And the film hasn't aged as well as it could have: by modern standards it drags on too long and one of the female leads is wooden and sounds like she's on barbituates most of the time. But it remains one of the most important films of the genre, and beautifully bridged the old-school trenchcoat-and-seedy bar flim noir era to a true 1950s Cold War paranoia genre, which left the world of crime fiction entirely and went thoroughly into horror. For the record, it's still a bit jarring to see Hammer nonchalantly get into a car after almost passing out from drinking an entire bottle of bourbon.
But it remains a bleak, nihilistic film in an era where heroes were expected to be rogues with a heart of gold, as opposed to just rogues. Heroes were expected to survive the end of the film and the authorities were supposed to save the day. If there were Cold War atomic secrets, there were spies involved: heavy hitters, James Bond types. Not bedroom peeping private eyes and mafia hoodlums, playing games over the end of the world like a baby innocently playing with a box of razor blades. And frankly, the kinds of discretionary things that were mandated by the standards of the day made the picture far more horrific: hearing screams and seeing just the business end of a set of pliers is somehow darker, and implies a gruesomeness far more vividly than Saw-level torture porn. Not seeing the obvious effects of the atomic fallout make it unclear who lives and who dies. In this film the police are more than indifferent to the game being played before them, they're just looking to swoop in and steal the spoils from the victor. It was a nasty, brutal little film made at a time where films tended to be more optimistic.
It's well worth seeking it out, even though these days you're looking at a Criterion Collection DVD or Blu-Ray, with the accompanying prices. But it's up there with the Maltese Falcon in terms of defining pictures of the genre, and up there with Angel Heart and Se7en in terms of twists on the genre. The "glowing box of death everyone wants" has had at least two shout-outs, namely Repo Man and Pulp Fiction, and the notion of a bomb that goes off when the spedometer trips a certain way was used as a plot device in Speed. It's a landmark in 20th century film worth a couple of cold martinis and some cool jazz to chill out with over an evening.