Barney Scott McGinnis and Luke Jeff Osterhage are two frontier gunslingers who, after a spree of dynamite-fueled bank robberies in the dying days of the Old West, are swept up by conscription into a U.S. unit headed for the muddy trenches of France in the midst of World War I. From the blistering glare of the frontline to the smoky chaos behind enemy lines, the pair soon discover that their fast-draw skills aren’t just for show; they prove themselves capable enough to survive the impossible and to improvise when conventional orders fail.
In the maelstrom of war, they cut a swath through danger by shooting down the pilot of a low-flying German bomber, sparking a wild chain of events that lets them slip away from their unit and slip into the role of impromptu officers. With the chaos as cover, the two improvise a raucous night in an officer’s mess, where bravado meets nerves and a challenge is issued: pilot a Vickers F.B.5, known as a “Gunbus.” They manage the flight, get wildly lost, and glimpse a towering German airship lurking in the clouds—an omen that seems too big to ignore. A chance landing at an RFC squadron base solidifies their fateful encounter with the airship, and the squadron commander, impressed by their audacity, offers them a slot in his ranks.
Still eager to escape the conflict, Barney and Luke seize another chance at freedom by stealing two more planes, intending to outrun the war and fly to neutral Switzerland. Their journey takes an unexpected turn when they stumble upon the airship’s hangar; Luke is shot down and taken captive, and Barney learns that the base he left behind has been reduced to ruins by the mysterious airship. With grit and a stubborn streak, he defies orders, retrieves the Gunbus, and makes a clandestine return to the hangar. There, he discovers Luke’s imprisonment in a bank vault—a setup that triggers his old habit of blowing open safes and vaults to free his friend, a daring move that sets the stage for a plan to take down the incredible airship itself.
The chase resumes in the sky as the airship lifts off, and Barney and Luke push the Gunbus into pursuit. They’re soon joined midair by the rest of the squadron, a motley crew guided by their eccentric engineer Fritz, the squadron’s wild ideas taking flight in a flotilla of improvised, carnival-like planes. Fritz, Ronald Lacey, lends his offbeat genius to the aerial combat, and the pilots weave through a furious dogfight with the airship—Barney and Luke clinging to the craft’s exterior while firing six-shooters and tossing dynamite to force the airship’s captain to surrender.
Meanwhile, back in the Old West, the two heroes resume their ground-based bravado, blowing up another bank and racing off on horseback as they have before the war—only to be pursued by a posse that’s certain they’ll be caught. In a final twist, the duo vanish from sight and then reappear overhead, flying the Gunbus once more as if the war had never ended. The credits roll on a pair who can’t decide between staying on the right side of the law or chasing another reckless adventure, mulling over whether to ride south to war-torn Mexico or to seek a quieter life somewhere beyond the horizon.
