The Shakiest Gun in the West

Jesse W. Heywood graduates from dental school in Philadelphia in 1870 and travels west to become a frontier dentist. He quickly realizes that life beyond the city limits will demand more grit than polish. His journey marks the clash between urban training and rugged frontier reality.

Two masked bandits ambush the stagecoach and steal its cargo. A posse captures one of them, Penelope 'Bad Penny' Cushing, who is offered a chance at pardon by leading a mission against smugglers. She conceives a plan to join a wagon train despite the rules against single women.

Penelope accepts a potential pardon if she helps track down a ring of gun smugglers tied to a local Indian tribe. To join the wagon train that will carry out the mission, she fabricates a sham marriage with Jesse. This is precipitated by the murder of her prearranged marshal husband.

Jesse and Penelope join the wagon train with the leader's approval through the sham marriage. The arrangement allows Penelope to pursue her undercover work while Jesse begins his frontier life in earnest. The duo present a united front to the rest of the travelers.

That night, Jesse eagerly anticipates his wedding night, unaware the marriage is not legal. Penelope investigates crates of 'Bibles' in the preacher's wagon, trying to uncover the smugglers' operation. Their ruse backfires when a camp confrontation forces them back to their wagons and everyone believes the tale.

As the wagon train nears town, a raid by local Indians begins. Jesse fumbles his six-shooter, while Penelope shoots the attackers with practiced precision. The siege ends with Jesse celebrated as a hero by the wagon train and the town.

The preacher, suspecting Jesse is a federal agent, hires Arnold the Kid to force a gunfight. Jesse practices while Penelope meets her contact in town. When Arnold makes a deadly move, Penelope shoots him from a window, furthering Doc Heywood's legend.

That night Penelope explains her true role to Jesse, acknowledging the deception used to aid the wagon train. Jesse, thinking himself a crack shot, offers to help, but Penelope apologizes and leaves, leaving him heartbroken. He is left to face the townspeople's judgment alone.

Penelope tries to escape to federal troops but is kidnapped by the preacher, his minion, and their Indian allies. They take her to the Indian village outside town. Jesse publicly admits his truth to the town, and the townspeople turn their backs on him.

Jesse infiltrates the village disguised as an Indian woman and frees Penelope. He proposes waiting for the tribe to get drunk to ease their escape. During a tense gun battle, his identity is revealed as he fights the preacher and his minion, and Penelope is briefly separated from him.

Jesse defeats the preacher and his minion in a gunfight, claiming victory for himself while not knowing that Penelope did not assist this time. The village chaos subsides as the moment looks like a solo win. The audience learns that Penny's help was not part of the plan this time.

Jesse returns with the village chief and tribesmen to town, having brokered peace and replaced the chief's missing teeth. He is reunited with Penelope, and the frontier audience recognizes their growing bond despite the earlier deception. Penny even handles a boastful rival with a quick knockout.