Kansas City Confidential is a 1952 American film noir and crime film directed by Phil Karlson starring John Payne and Coleen Gray. The film was released in the United Kingdom as The Secret Four. Karlson and Payne teamed a year later for 99 River Street, another film noir, followed by Hell’s Island, a film noir in color.

Plot
A nameless, ruthless man (Preston Foster) who identifies himself as Mr. Big is timing to the minute the arrival of two trucks. One is an armored car routinely picking up bags containing lots of money from a bank. The other truck delivers to a flower shop next door. The man’s timing shows that, for a very few minutes, the schedule of both trucks coincidentally parks them next to each other. He is casing the armored car. He needs a gang to help him rob it. He selects three men for the gang—the addictive gambler Peter Harris (Jack Elam) wanted for murder, gum-chewing thug Boyd Kane (Neville Brand) and the womanizing Tony Romano (Lee Van Cleef). When interviewing them, he wears a mask so they cannot identify him. He has selected them because each has a reason for fleeing the US. They will fit perfectly into Mr. Big’s complex plan, which appears to be an ordinary robbery but is much more.

Part of his plan involves making an innocent patsy out of the floral truck driver and ex-con Joe Rolfe (John Payne), a look-alike getaway truck that the police will pursue instead of Mr. Big’s truck, to buy time to successfully escape the country. The robbery and pursuit go just as Mr. Big has planned. Each wearing a mask so none can identify each other, he and his gang arrive in a look-alike floral truck as Rolfe, unaware, drives away. Big and his gang subdue the armored car guards in four minutes, grab bags containing $1.2 million and flee, knowing that his distinctive getaway truck will be mistaken for Rolfe’s. Escaping, Mr. Big gives each gang member a torn king playing card. He tells them “Hang on to those cards. We’ll cut up the money when I think it’s had time enough to cool off. I’ve got everything covered, but in case something does go wrong, and I can’t make the payoff myself, the cards will identify you to whoever I send with the money.” When the gang members object, Big tells them, intensely, “You can’t even rat on each other because you’ve never seen each other without those masks. I’ve made you cop-proof and stoolpigeon-proof and it’s going to stay that way. Keep those masks. You’ll be wearing them at the payoff.” The mystery man sends the other three to other countries to wait for the final payout.

As Mr. Big has planned, the police, brutal, corrupt and somewhat stupid, run down Rolfe and, wrongly concluding that since he’s an ex-con he must have been one of the robbers, submit him to third-degree grilling, but he maintains his innocence. Finally, he is released when his alibi checks out and the real getaway truck is found, and the bank’s insurance company tells him that, if he should happen to run across the stolen money, they will pay a 25% reward. As he’s released, Rolfe, a Bronze Star and Purple Heart-earning former Soldier accustomed to hardship, sees that he’s lost his job; he’s broke and everything he’s worked for since he got out of prison is ruined. After three weeks of unemployment and the prime suspect on the pages of every newspaper, he is at the end of his rope. He decides that, with nothing to lose, he will find the criminals and clear his name. Confiding his plan to a bartender friend with ties to the underworld, the friend tells of rumors that gambler Peter Harris, wanted and with no money or way of escape, suddenly has money and has fled the city. Believing Harris must be one of the robbers, Rolfe pursues him to Tijuana and looks for him in illegal gambling joints.

Finding Harris, Rolfe follows him to his hotel room and, finding the mask Harris wore, beats him into revealing the Mexican resort of Barados as the gang’s meeting place. He tells Harris, “I’m moving blind, but I got you for a bird dog to point the way as we go along.” At the airport, waiting for the flight to Barados, the police recognize Harris and, thinking he is reaching for a gun, kill him. Rolfe, not sure what to do next, realizes he can impersonate Harris when the airport clerk hands him Harris’ claim checks. In Harris’ luggage, he finds the mask and the torn playing card.

Arriving in Barados as Harris, Rolfe meets Kane, whom he identifies as one of the robbers because he chews gum constantly, and Romano, who Rolfe decides is a gang member because he has arrived almost simultaneously at the same time as Kane. Unknown to Rolfe, Mr. Big is there, too. His name is Tim Foster, and a conversation with a friend, Scott the insurance investigator, reveals his reason for the robbery. Foster never intended for the three goons to split the money and get away with their shares. He was planning to spring a trap on them—as though he had solved the robbery himself—and so reclaim his job with the Kansas City police. His plan is to double-cross his gang, turn them and the money in, collect the 25% reward, and get his job back. The conversation reveals that he was a 20-year police captain who was forced to retire prematurely by political opponents.

But Foster’s plan suddenly is skewed when his daughter Helen (Coleen Gray) arrives unexpectedly. She meets Rolfe while registering for a bungalow and takes a liking to him. She’s studying law and ready to pass her attorney’s exam. She tells her father that, like a courtroom argument, she has presented his case of premature retirement to Kansas City’s mayor and the mayor has agreed to reconsider putting Foster back on the force. Foster, seeing his plan threatened, tells Helen he doesn’t want to return, but will consider her proposal. She then shocks him by telling that she’s met Peter Harris and likes him.

That night, in a poker game, Rolfe sits in and deliberately drops the torn king card, sarcastically saying, “My good luck piece. Souvenir of the biggest pot I ever sat in on.” Kane and Romano react, but Foster does not, because only he knows that the man pretending to be Harris, isn’t. Rolfe catches Romano searching his room and, after Rolfe beats him and he submits, the two men identify each other as gang members and agree to cooperate until the money is split.

In the meantime, Rolfe has met Helen and likes her. They tease each other, with Helen threatening to cross-examine him because he will not tell her much about himself. Later, Rolfe meets Foster and tells him he can’t join the poker game because he’s taking Helen to dinner. Returning to his room, he’s beaten by Romano and Kane, who reveals he knows Rolfe is an impostor because he and the real Harris were in prison together. They are about to take Rolfe into the jungle to torture and possibly kill him when Helen knocks on the door and saves him. Later, Foster appeals to Helen to forget Rolfe, but she refuses.

Foster is now ready to carry out the double-cross. He writes individual notes to Rolfe, Kane, and Romano to meet him on his boat, the Mañana, where the three will all coincidentally be, ripe for pickup by the police. Before that can happen, Kane and Romano try to ambush Rolfe, who gets the drop on them, admits he’s Rolfe, not Harris, and makes them believe he’s after Harris’ share. At the same time, Helen tells her father she knows Rolfe is in trouble. Once again, he fails to persuade her to stop seeing Rolfe.

Kane and Romano are not finished with Rolfe. They waylay Rolfe and discover he’s going to the boat. All three are driven there by Foster, who they still don’t know is Mr. Big. On board the boat, Rolfe escapes and finds the stolen money in a cabinet. Romano, gun in hand, confronts him. Rolfe shows him where the money is. Romano, greedy, kills Kane and is ready to take all the money and kill Rolfe, but Foster, trying to save his unraveling plan, intervenes. But he slips and reveals he is Mr. Big. In a resulting gun battle, Foster kills Romano but not before Romano shoots him. As Foster is dying, he tells Rolfe his one wish is that Helen doesn’t find out his duplicity. With his dying breath, he tells insurance investigator Scott that Rolfe deserves the 25% reward of $300,000.

Rolfe and Helen comfort each other after her father’s death. Later, Rolfe asks Scott how she’s taking it. Scott gestures at Helen and says meaningfully to Rolfe, “Why don’t you ask her?” She smiles in emotional release, and they kiss.

Cast
John Payne as Joe Rolfe
Coleen Gray as Helen Foster
Preston Foster as Tim Foster
Neville Brand as Boyd Kane
Lee Van Cleef as Tony Romano
Jack Elam as Pete Harris
Dona Drake as Teresa
Mario Siletti as Tomaso
Howard Negley as Andrews
Carleton Young as Martin
Don Orlando as Diaz
Ted Ryan as Morelli