Lt. Peter Sterling is a capable U.S. Army officer who, through a comic-age mix-up, is mistaken for his Navy look-alike, Bosun's Mate 'Slicker' Donevan, and whisked away to the Coronado base. Accompanying him is his wry guide, Francis, whose quips and hints help steer the misadventure, even as Sterling tries to keep his head above water in a world that blends army protocol with naval bravado.
The trouble compounds when Sterling is mistaken for Slicker and promptly arrested by MPs. His insistence that he’s the wrong man lands him in the base’s psychiatric ward, under the care of Commander Hutch, a semi-dazed superior who isn’t fully sure what to make of the whole affair. Francis, ever the voice of reason or at least the most entertaining mischief-maker, advises that the only way out is for Sterling to pretend to be Slicker. The plan, of course, is fragile and fraught with risk, but it seems like Sterling’s best bet to regain his freedom.
As the impersonation kicks into high gear, Sterling must endure a boxing exhibition against the bruising opponent known as Bull Bostwick, a test that is as much about nerve as it is about skill. The ring becomes a stage for farce and fitness, with Francis occasionally tipping the scales by pulling little tricks to influence the outcome, though not always in Sterling’s favor. Meanwhile, Sterling’s personal life becomes tangled when he finds himself attracted to the nurse Betsy Donevan, a woman who turns out to be his supposed sister in this convoluted identity game.
Slicker, for his part, relishes the comedy and the chaos, and he shows a stubborn reluctance to help Sterling whenever the plan seems to require his cooperation. The farce ramps up when a massive Army vs. Navy war games exercise is announced, and Slicker resolves to step back into the Navy fold. But on the day of the Games, Slicker is knocked out cold in the infirmary, a mishap traceable to Peter’s own clumsy missteps.
The mission grows increasingly elaborate when Sterling is tasked with driving a DUCK—an amphibious vehicle—on a critical supply run. A heavy fog compels the convoys to beach far from their target, forcing a long and winding drive along highways that serpent around a mountain range. A traffic jam strips away two of Sterling’s shipmates, and a stubborn gas shortage complicates the journey further. A service station attendant refuses to grant free gas, prompting Francis to stage a dramatic intervention that ends with a pump being kicked and a gasoline leak being conserved for the mission.
As their voyage continues, the brass decide to keep the incident under wraps, choosing silence over spectacle. The result is a tangle of mistaken identities that seems almost destined to stay unresolved, even as the higher-ups shuffle the paperwork and the MPs keep circling. In the end, Sterling must endure a train ride home hidden away in the baggage car with Francis, continuing the comedy of errors that has defined his unlikely military cross-branch misadventure.
Throughout the escapade, the film lingers on the comic tension between duty and disguising one’s true role, using a mix of quick-witted dialogue, absurd scrapes, and a sense of wartime chaos that keeps the tone light yet pointed. The pairing of Sterling’s earnestness with Francis’s sly pragmatism anchors the story, and Betsy Donevan’s presence adds a personal stake that humanizes the farce. The result is a lighthearted, fast-paced comparison of two military worlds, rendered with warmth and a steady sense of humor.
