Jerome Stewart William P. Carleton throws an elegant dinner party to announce his engagement to Ursula Chesebrough Betty Blythe, but the news lands as a total surprise for his daughter Mona Dorothy Libaire, who doesn’t take kindly to Ursula and reacts with a mixture of resentment and hurt. A longtime admirer and inebriate, Ronnie Van Zandt Richard 'Skeets' Gallagher steps in with a reckless plan: he convinces Mona to run away and elope with him, though she does not truly love him. The hopeful pair board a train bound for Buffalo, but Mona soon reconsiders and steps off at a whistle stop, hoping to hire a car to Albany. Instead, she ends up hiring David Mannering David Manners as he steps out of a café. He drives her to a remote area, robs her, and leaves her stranded. Later, he returns and agrees to drive her toward her desired destination, while Mona feigns a sprained ankle to evoke sympathy. The car becomes mired in mud, forcing them to spend the night inside the vehicle until help arrives at dawn.
As the hours pass, Mona grows more intrigued by David, who reveals he was released from prison only a month earlier and had previously worked as a bank teller accused of theft—though he insists he didn’t commit the crime. Jerome and Ronnie eventually trail Mona to the whistle stop, only to learn that Rourke wasn’t hired by Mona; nonetheless, they hire him to drive them to Albany. A separate scare—the sight of a charging bull—drives Mona to flee, and David notices her ruse. When they reach Albany, David plans to meet a man named Delaney [Robert Gleckler] for work at a bowling alley and pool hall. He tries to coax Mona out of the car to draw a crowd, but she tells a policeman that she and David are newlyweds arguing over their honeymoon plans.
Before David can see Delaney, Sid Barkley [Ralf Harolde] and Butch Carter [Ernie Adams] arrive with a different demand: $10,000 as their share from a previous job for which they took the rap. Delaney refuses, and Carter stabs him in the back. The two criminals ransack the office and flee, while Delaney manages to hide a crucial note inside a bowling pin. David discovers Delaney on the floor, whispering “the pin” just before dying. Fearful of being implicated in the murder, David escapes with Mona in tow.
With David as the sole witness, the police close in on him and Mona. Both are arrested for Delaney’s murder, and Mona’s father, Jerome, visits the jail to learn the truth. Mona confesses that she loves David and believes he is innocent, urging her father to secure their release. Jerome then confronts David, who refuses paternal intervention and asks Jerome to free his daughter instead. The elder Stewart suggests Mona forget David, since his fingerprint was found on the knife, casting him as the primary suspect. Yet Mona remains convinced of David’s innocence and insists she saw two other men leaving Delaney’s place.
As the mystery deepens, Mona and Ronnie chase clues about what Delaney meant by “the pin” and search Delaney’s office for any hint. Barkley and Carter arrive to retrieve the letter they left behind, and when Mona phones the police just as they enter, a tense chase ensues through the back corridors. Mona discovers Barkley and Carter’s letter folded inside a hinged bowling pin on the floor, and the two men finally confess. With the charges against David dropped, Mona and David are reunited, and their future finally looks brighter after the perilous entanglements that tested their trust and resolve.
