Plot
Insurance investigator Sam Donovan (O'Keefe) arrives in a small Midwestern town west of Chicago to investigate a recent death. Leaving the train, he meets attractive young Anita Weatherby (Britton), who fumbles with an armload of Christmas gifts he helps her corral. They take the same bus to Cleberg, forming a mutual attraction.
The Weatherby family is there to greet Anita, father Stu, president of the local bank, beaming beneath his signature heirloom beaver coat. Mistaking the handsome man for a beau being brought home to meet them over the Holidays - and if anything disappointed to discover he is not - they invite Donovan to drop by the house.
At the Marlowe County sheriff's office Donovan learns from a reticent Sheriff Larry Best (Bendix) that local curmudgeon Roger Phillips' death appears to be a suicide. A cursory probe disagrees: there were no powder burns on the victim, no pistol was found, no bullet retrieved, and there is no coroner's report. Nor is Sheriff Best in any rush to get one. Donovan smells murder.
Leaving Best's office in a dudgeon, he is halted by the tinkling of a bullet and shell casing before the door can slam. Donovan immediately identifies them as coming from a Luger. Best indicates the pistols are not uncommon in town (as many had been brought home as war prizes by recently returned veterans of World War II) and volunteers even he owns one.
An interview with the local jeweler who found Phillips' body yields nothing but a stonewall. Any way Donovan turns the message is the same: Phillips was roundly hated, nobody is sorry he was dead, and no-one cares how.
Even the policy's double-indemnity payout for murder is not enough to elicit cooperation from its beneficiary, Phillips' niece Margaret Baker, nor her newly wed husband, Frank, Donovan's top suspect. The couple had quarreled with Phillips over his objection to their marriage, then left for the bus station to elope. Frank claims he stayed there, Donovan has his doubts.
With Christmas shortly approaching everything begins to drag, and Donovan is forced to stay longer in town than he had anticipated. Best encourages the dogged gumshoe to just relax and have a good time. He can't: he has a job to do, and his company is on the hook for an extra $20,000 if the death proves to have been murder...but a chance sighting of Anita steers him avidly in the pursuit of l' amour.
Calling on her, Donovan is warmly welcomed by the Weatherbys, and begins genteelly courting. Father Stu is stalwart, wife Bessie is approving, and romance-crazed teenage Cathie goes head over heels for the charismatic new presence in their home. Busybody maid Hilda, a longtime fixture accustomed to maternally meddling in family affairs, is also smitten, but maintains a wary eye.
At the annual town Christmas tree lighting the residents are grieved to learn that beloved longtime physician Dr. Gerrow, who presides over the festivity and delivered half the folks in the crowd, has died of a heart attack. Complications ensue when Donovan finds that Stu had owned a Luger he'd brought back from World War I, but given to Gerrow for his gun collection some months earlier.
Seeking to hide her diary from her prying sister, Anita accidentally stumbles into her father's Luger, secreted in the Weatherby home. She immediately suspects him of the killing, and conceals her discovery.
To smoke the murderer out Donovan plants a story in the local newspaper stating that he has summoned a forensic police chemist to uncover clues of the killer's identity still present at the Phillips home. The dried residue of a puddle of water found near the deceased's body is sure to include fibers from the assailant's jacket, or other telltales shed off it.
The town grows atwitter at the prospect. Hilda burns Stu's heirloom beaver coat, caught in the act by Donovan.
With the scientist's arrival imminent, Donovan heads to the Phillips home. Sheriff Best beats him there, correctly suspecting the story had been a fake. The two face off to a tense stalemate. Stu arrives next, with Anita hot on his heels.
Donovan accuses Stu of the crime, but when reenacting it realizes the murderer could not have been right-handed. Immediately, it gels for him that Dr. Gerrow's pen holder had been on the opposite side of the desk when he'd once reached for it to leave a note, and Gerrow had stood out as a southpaw in a photograph of a four-man pistol team hanging amid his gun collection. Weatherby then confesses what had happened: he'd come upon Gerrow just after the doctor had snapped and shot the man responsible for so many decades of misery among the townsfolk. Taking the Luger away, he'd talked Gerrow out of turning himself in until after the Holidays.
Swayed by Weatherby and Best, Donovan finally concludes that the town will be better off if Dr. Gerrow's memory is preserved. With an eye toward settling there - and wedding Anita - he agrees to keep his company paperwork trail buried, and see that the $20,000 murder indemnity is quietly paid to a charity as Margaret has requested. All are in accord on his Solomonic solution to the town's trial.
