Innerspace

In the bustling metropolis of San Francisco, a downtrodden U.S. Navy aviator named Lt. Tuck Pendleton (played by) finds himself at a crossroads, resigning from his commission to participate in a clandestine miniaturization experiment. He and his submersible pod are shrunk to the microscopic level and transported into a syringe, destined for injection into a rabbit. However, the lab is suddenly infiltrated by a rival organization, led by the cunning Dr. Margaret Canker (played by), who seeks to usurp the experiment and pilfer its revolutionary miniaturization technology.

As chaos erupts, the experiment's supervisor, Ozzie Wexler, seizes the initiative and flees with the syringe, pursued by one of Canker's henchmen, Mr. Igoe (played by). The chase culminates at a nearby shopping mall, where Igoe ultimately takes down Ozzie in a hail of gunfire. In a desperate bid to prevent the experiment from falling into enemy hands, the wounded Ozzie injects Tuck and his pod into an unsuspecting bystander - Jack Putter, a hapless Safeway grocery clerk who is subjected to his boss's tyranny and belittled by his shallow coworker, Wendy.

As Tuck regains consciousness, he finds himself perplexed by his predicament, believing he has been injected into the rabbit. Frustrated attempts to contact the lab yield nothing, prompting him to utilize his pod's camera capabilities to peer through Jack's optic nerve and gain insight into their surroundings. Upon realizing that he is actually lodged within a human host, Tuck endeavors to establish communication by affixing an earpiece device to Jack's inner ear. Through this means, he begins conversing with Jack, explaining the dire circumstances of his predicament and pleading for assistance in securing his extraction from the human body.

Back at the lab, scientists reveal to Tuck and Jack that the rival group has pilfered one of two crucial computer chips vital to the experiment's success. The mastermind behind this dastardly act is none other than Victor Scrimshaw (played by), whose henchmen include Dr. Canker, Mr. Igoe, and "The Cowboy" (played by).

As Jack (character) navigates the complex web of deceit, he initiates contact with Lydia Maxwell, a tenacious reporter with ties to The Cowboy. Her expertise proves invaluable as they uncover his plan to procure the coveted computer chip from Scrimshaw. With The Cowboy's whereabouts revealed, Jack and Lydia stake out his hotel, their attention drawn to a local nightclub where they observe him making moves. It is here that Jack encounters Wendy, whose growing suspicion about his double life prompts her interest in him. Meanwhile, Jack's pursuit of The Cowboy leads him to the hotel, where he confronts the cowboy himself. In a daring move, Tuck uses the pod's technology to reconfigure Jack's facial features, transforming him into a doppelganger of The Cowboy. As they pose as their target, Lydia and Jack (in disguise) meet with Scrimshaw, poised to steal the chip from his grasp. However, just as they are about to seize it, Jack's increasing nervousness betrays the deception, exposing the ruse to Igoe. Captured and taken to the laboratory, Jack and Lydia find themselves imprisoned alongside their adversaries.

In the confines of their cell, Jack and Lydia share a poignant moment, their lips touching in a kiss that unwittingly transfers Tuck into Lydia's body through the medium of their saliva. As they are whisked away to the laboratory, the criminals inject Igoe into Jack's system, aiming to locate Tuck, eliminate him, and claim the remaining chip attached to the pod. Upon being released from their prison, Jack and Lydia take control of the miniaturization device, unwittingly shrinking everyone within its confines while attempting to retrieve the coveted chip. Meanwhile, Tuck, now inhabiting Lydia's body, discovers a growing fetus and realizes she is pregnant with his child. By exploiting her eardrum as a resonance chamber, he utilizes their shared tune (Sam Cooke's "Cupid") to alert Jack and Lydia to this unforeseen development. In response, they share another kiss, unwittingly transferring Tuck back into his own body.

With the chaos unfolding around them, Jack and Lydia frantically drive back to the laboratory in an effort to enlarge Tuck. Unbeknownst to them, the shrunken Scrimshaw and Canker have escaped and are hiding in the backseat. As they attempt to subdue their captors, Igoe locates Tuck within Jack's esophagus and launches a counterattack. Tuck disables his pursuer's craft before dropping him into Jack's stomach, exploiting the latter's anxiety to amplify his stomach acid and ensure Igoe's demise.

As Jack's air supply dwindles in the pod, he must employ a drastic yet ingenious solution to escape his claustrophobic confines. With mere minutes of supplemental oxygen left, Jack exploits his hairspray allergy by inducing a powerful sneeze, successfully ejecting the pod and expanding it to accommodate his growing stature. Reunited with Lydia at last, Jack is finally able to meet her in person, and the two share a long-awaited moment of connection.

The celebration continues as Tuck and Lydia exchange vows at Wayfarers Chapel, where Tuck wears the experiment's chips as cufflinks, a symbol of their extraordinary journey together. As they depart in their limousine, Jack can't help but feel a sense of triumph and newfound confidence. Little does he know, however, that The Cowboy is behind the wheel, and Scrimshaw and Canker are hiding in plain sight - or rather, inside a suitcase in the trunk.

Empowered by his experiences, Jack makes a series of bold declarations: to his doctor, he announces he's overcome his affliction; to Wendy, he declares she has no chance with him; and to his manager, he submits his resignation. With his newfound sense of control and purpose, Jack jumps into Tuck's vintage 1967 Mustang, hot on the heels of the limousine in a daring bid to rescue the newlyweds and reclaim his place in the world.