Private detective Philip Marlowe (George Montgomery) is summoned to the Pasadena mansion of wealthy widow Mrs. Elizabeth Murdock (Florence Bates), and meets Mrs. Murdock's lovely, neurotic secretary, Merle Davis (Nancy Guild). Marlowe is interested in Merle, and irritated by Mrs. Murdock's spoiled son, Leslie Murdock (Conrad Janis).

Mrs. Murdock asks Marlowe to find her missing "Brasher Doubloon", a rare and valuable coin from her late husband's collection. Mrs. Murdock intimates she knows who the thief is, but refuses to tell Marlowe, who then informs Merle he's declining the case because she's not being completely honest. However, Merle's pleas change Marlowe's mind.

Eddie Prue (Alfred Linder), a hood working for nightclub owner and gambler Vince Blair (Marvin Miller), confronts Marlowe when he returns to his office, and tries to intimidate him to drop the Murdock case. Marlowe tosses him out, then visits Elisha Morningstar (Houseley Stevenson), a coin dealer. Morningstar confirms someone tried to sell him the coin, and opines the offer was a ploy to get him to authenticate the coin, but he refuses to tell Marlowe the name of the seller. After he overhears Morningstar call a private detective, George Anson (Jack Conrad), Marlowe goes to Anson's apartment and discovers that Anson has been murdered. Marlowe finds a small revolver next to Anson's body, and recognizing that it belongs to Merle, asks her about her involvement with Anson, the coin and the Murdocks. Crying, Merle tells him that Mrs. Murdock has found the coin, which Leslie had "borrowed" to pay a gambling debt. Merle also reveals that Mr. Murdock used to harass her when she was his secretary, and that she has since had a fear of being touched.

Marlowe then questions Mrs. Murdock and reveals that he has the real coin, and she is therefore lying about having recovered it. Marlowe leaves. Mrs. Murdock orders Merle to get the coin from him any way she can. Marlowe returns to his apartment and is confronted by Rudolph Vannier (Fritz Kortner), a former newsreel cameraman who claims the doubloon has been promised to him.

That evening, Merle goes to Marlowe's apartment and nervously attempts to seduce him. Although Marlowe is interested in the young secretary, he does not give her the coin.

Marlowe is awakened by a call from Merle, who tells him to come to Vannier's home. There, Marlowe finds Vannier's corpse and a distraught Merle, who claims that she came to demand Vannier's blackmail film. When Leslie enters, Marlowe realizes that he is involved, grabs him and the film, then turns Leslie over to the police.

At the office of Police Homicide Detective Lt. Breeze (Roy Roberts), Marlowe reveals that Leslie intended to give the coin to Prue and Blair, who would turn it over to Vannier in exchange for the film, with which they would then blackmail Mrs. Murdock. Leslie killed Anson and Morningstar when they threatened to upset his plans, and Mrs. Murdock killed Vannier when she learned of Leslie's plans to continue the blackmail. Marlowe then shows Vannier's newsreel footage, which reveals that Mrs. Murdock, not Merle, killed Mr. Murdock.

Mrs. Murdock confirms her guilt, but states that she has taken her revenge for Mr. Murdock's infatuation with Merle by aggravating Merle's neurosis and making her terrified of men. After the Murdocks are taken away, Marlowe comforts Merle, who states her intention to stay with him until her fear of being touched is erased.

A 1947 American film-noir crime film (known in the UK as "The High Window") directed by John Brahm, produced by Robert Bassler, screenplay by Dorothy Bennett (as Dorothy Hannah) and Ring Lardner Jr., adaptation by Leonard Praskins, based on Raymond Chandler's novel "The High Window" (1942), cinematography by Lloyd Ahern Sr., starring George Montgomery, Nancy Guild, Conrad Janis, Roy Roberts, Fritz Kortner, Florence Bates, and Marvin Miller.

Fred MacMurray, Victor Mature, and Dana Andrews were all mentioned at different times as having been cast as Philip Marlowe in the film before the studio settled on George Montgomery, appearing in the final film of his 20th Century Fox contract.

"The High Window" had already been adapted for film in 1942 as a Michael Shayne adventure starring Lloyd Nolan.