Crooked political boss Paul Madvig (Brian Donlevy) is determined to back reform candidate Ralph Henry (Moroni Olsen) for governor after falling in love with Henry's daughter, Janet (Veronica Lake). Madvig's right-hand man, Ed Beaumont (Alan Ladd), believes the move is a big mistake and rightly distrusts Janet's motives. She is only playing along at her father's request; she is put off by Madvig's crudity and becomes very attracted to the more eclectic Beaumont. He fends off her advances out of strong loyalty to his friend. The deluded Madvig boasts that Henry has practically given him the key to his house; Beaumont warns him that it is liable to be a glass key, one that can break at any moment.
When Madvig tells gangster Nick Varna (Joseph Calleia) that he is cleaning up the city and that Varna will no longer receive protection from the police, Beaumont grows even more concerned. Complicating matters further, Henry's ne'er-do-well son, Taylor (Richard Denning), owes Varna for gambling debts, while Madvig's young sister, Opal (Bonita Granville), is in love with Taylor. When Madvig finds out, Opal fears what he will do to her boyfriend.
Beaumont later finds Taylor's lifeless body in the street. Madvig is the prime suspect, much to Varna's delight. When Varna hears that Beaumont and Madvig have split over the Henry mess, he also tries to recruit Beaumont. Beaumont turns him down, so Varna has him brutally beaten repeatedly by sadistic henchman Jeff (William Bendix) to torture him into revealing details of corruption to the editor of the newspaper Varna controls. Beaumont contrives an escape and is hospitalized. When Beaumont recovers, he learns that Varna has found a "witness" to Taylor Henry's killing, a man named Sloss (Dane Clark). Madvig has Sloss brought to his office, but Sloss is gunned down before he can talk. As a result, Madvig is indicted for the murder and held in jail.
Beaumont finds a somewhat drunk Jeff in a bar and tries to pump him for information in a back room. As they drink, Beaumont toasts, "Here's looking at you." Just as Jeff starts to talk, Varna shows up and brusquely orders him to shut up. When Beaumont disarms Varna, a fed-up Jeff strangles his boss. After Jeff is finished, Beaumont gets the waiter to call the police to arrest Jeff. Having finally guessed who killed Taylor Henry, Beaumont persuades District Attorney Farr (Donald MacBride) to arrest Janet. As Beaumont had hoped, her father confesses he struggled with his son, causing Taylor to fall and strike his head. Afterwards, Madvig overhears Janet tell Beaumont that she loves him and that she knows he loves her. Seeing that it is true, Madvig gives the couple his blessing (but takes back his expensive engagement ring).Brian Donlevy as Paul Madvig
Veronica Lake as Janet Henry
Alan Ladd as Ed Beaumont
Bonita Granville as Opal "Snip" Madvig
Richard Denning as Taylor Henry
Joseph Calleia as Nick Varna
William Bendix as Jeff
Frances Gifford as Nurse
Donald MacBride as District Attorney Farr
Margaret Hayes as Eloise Matthews
Moroni Olsen as Ralph Henry
Eddie Marr as Rusty
Arthur Loft as Clyde Matthews
George Meader as Claude Tuttle
Dane Clark as Sloss (uncredited)
Dashiell Hammett's The Glass Key had been filmed by Paramount in 1935 as a vehicle for George Raft. They still had the film rights in 1941, when Alan Ladd impressed Paramount executives while shooting This Gun for Hire. Even before the film was released, head of production Buddy de Sylva announced the studio would star Ladd in his own film as a follow up. Hammett's reputation was strong in Hollywood following the success of The Maltese Falcon and Paramount decided on a new version of The Glass Key; De Sylva said the studio wanted a "sure fire narrative to help him [Ladd] on his way," said De Sylva.
Production was announced in October 1941. Two months later Paramount said that Ladd would make Red Harvest, from another Hammett novel, instead of The Glass Key, with Jonathan Latimer to write the script and Fred Kohlmar to produce. Brian Donlevy was assigned to co-star.
However these plans changed again - Red Harvest was postponed (it was never made) and The Glass Key was re-activated, with Donlevy and Ladd to star. Stuart Heisler was assigned to direct.
Paulette Goddard was originally meant to be the female lead but had to drop out due to other commitment. She was replaced at first with Patricia Morison, but after seeing Lake and Ladd together in This Gun for Hire it was decided to replace Morison with Veronica Lake. Lake was going to be making I Married a Witch but filming of that was postponed when Joel McCrea turned down the lead role.
Bonita Granville, Richard Denning and Joseph Calleia were assigned supporting roles. Old time movie stars Maurice Costello, Jack Mulhall and Pat O'Malley played minor roles.
The staff at Variety magazine gave the film a favorable review, writing, "Parading a murder mystery amidst background of politics, gambling czars, romance and lusty action, this revised version of Dashiell Hammett's novel—originally made in 1935—is a good picture of its type...Mixed well, the result is an entertaining whodunit with sufficient political and racketeer angles to make it good entertainment for general audiences. Donlevy makes the most of his role of the political leader who fought his way up from the other side of the tracks."
Critic Dennis Schwartz wrote, "The film is mostly done for entertainment purposes, as it lightly skips over the corrupt political process as merely background for the unlikely love story developing between the engaging Lake and the deadpan Ladd. The film had many undeveloped film noir themes used by other films. Howard Hawks's The Big Sleep borrowed freely from The Glass Key."
Critic Hal Erickson wrote, "Dashiel Hammett's The Glass Key, a tale of big-city political corruption, was first filmed in 1935, with Edward Arnold as a duplicitous political boss and George Raft as his loyal lieutenant. This 1942 remake improves on the original, especially in replacing the stolid Raft with the charismatic Alan Ladd...Far less complex than the Dashiel Hammett original (and far less damning of the American political system), The Glass Key further increased the box-office pull of Paramount's new team of Alan Ladd and Veronica Lake."
The Glass Key was presented on Hollywood Players November 26, 1946. Gene Kelly played Ned Beaumont in the adaptation.