In futuristic 1987, astronaut William “Buck” Rogers blasts off on a solo mission aboard Ranger Three, the last deep space probe of the National Aeronautics and Space Administration (NASA). After encountering a violent meteor shower, the spacecraft is thrown out of orbit and drifts off course. The life support system freezes, keeping Buck preserved in a cryogenic state. Centuries later, in the year 2491, Ranger Three is picked up by a flagship belonging to the Kingdom of Draconia, whose advanced technology helps Buck regain consciousness. Kane, an advisor to the Draconian Royal Family, informs Princess Ardala, the commander of the flagship, that the intruder and his antiquated spacecraft appear to be over 500 years old. After Buck introduces himself as a captain of the U.S. Air Force, Kane notifies him that he is now a captive of the powerful Draconian Dynasty, which controls seventy-five percent of the universe. While Buck rests, Kane tells Ardala that he suspects Buck is a military spy for the Federal Directorate of Earth, sent to inspect the Draconian flagship for illegal arms in anticipation of the upcoming peace and trade talks between the two empires. In a plan to expose Earth’s defense shield and to test his spy theory, Kane programs Ranger Three to return Buck to Earth and hides a micro-transmitter on board. If Buck is a spy for Earth, he will be escorted through a secret channel in the planet’s defense shield, and the transmitter will relay the coordinates to the Draconian flagship, providing valuable intelligence for a surprise attack. If Buck is unknown to the authorities on Earth, he will incinerate on re-entry. Within Earth’s airspace, a squadron of military spacecraft commanded by Colonel Wilma Deering intercepts Buck. Unfamiliar with his strange lingo and outdated vessel, they guide him to a docking bay on Earth, detaining him for interrogation and study by Doctor Huer, a leader within the Federal Directorate. During his stay, Buck is assigned a drone assistant named Twiki who carries a talking artificial intelligence computer known as Dr. Theopolis. Although Huer and Theopolis believe Buck is not a threat, Wilma remains distrustful, believing he might be a spy for space pirates. Meanwhile, Buck tries to comprehend that the world he knows is gone and he has arrived in the 25th century. During a tour, Wilma explains that after the nuclear holocaust, Earth’s civilization gradually reestablished itself and built The Inner City near the former Chicago, Illinois. Outside of this modern capital, however, are scorched ruins and a barren wasteland, which is the reason why Earth is dependent on other planets for resources. The purpose of the upcoming trade talks is to seek the Draconians’ cooperation in defending supply routes from pirates and to offer in exchange, landing privileges on Earth. When Buck notices a burn mark on the outside of Ranger Three, he suspects that the Draconians fired on him before towing the spacecraft and warns Wilma that the Draconian “peace” envoy could be secretly armed. After the micro-transmitter is discovered inside Ranger Three’s navigation system, Buck is tried for espionage. Despite testimony that he is a mere pawn, the court finds him guilty of spying and sentences him to termination. However, Wilma gives Buck another chance to prove his innocence by accompanying him on a visit to see Kane and Ardala, whom Buck claims can verify his story. Welcoming them on board the Draconian flagship, the princess appears hospitable, but lies and states that she does not recognize Buck. The greeting is interrupted when Draconian fighter ships, disguised as pirates, pretend to attack their own flagship to avoid any suspicion that Draconia is the real force behind the “pirate” raids on Earth’s shipping lanes. Displaying his dogfighting skills, Buck helps Wilma defeat the hostile assault. At a formal ball on Earth to celebrate the arrival of the Draconian trade delegation, Buck is permitted to attend because Ardala wants to thank him personally for his heroism against the pirates. Meanwhile, Buck reminds Wilma to be wary of Draconians. After the celebration, Buck accepts Ardala’s invitation to return with her that evening to the flagship, unaware that his guardians, Theopolis and Twiki, are following him. In her private chamber, Buck pours Ardala a drink and discreetly mixes it with a powerful relaxant, while the lustful Ardala offers Buck the opportunity to form a powerful new dynasty with her. After Ardala passes out, Buck disarms her bodyguard and infiltrates the docking bay disguised as a Draconian soldier. When the princess wakes, she issues orders for an immediate attack of Earth, despite Kane’s advice to wait for support from King Draco’s forces. After observing warships in the docking bay, Theopolis and Twiki realize that the peace mission was a hoax. As soon as they see Buck dressed as the enemy, they assume he is abetting the Draconian attack. On Theopolis’ instruction, Twiki threatens Buck with a laser weapon. Buck tries to persuade the robots he is on their side and is attempting to sabotage an attack by loading explosives in the tailpipes of enemy warships. Buck explains that the pirate raids were a Draconian ploy to force Earth into a treaty. Theopolis believes Buck and alerts The Inner City to the surprise attack. Thanks to Buck’s strategy, the Draconian warships explode as they launch, allowing Wilma and her Directorate fighters to concentrate their firepower on the undefended Draconian flagship. As Kane and Ardala escape in an emergency shuttle to rendezvous with King Draco’s fleet, Wilma rescues Buck, Theopolis and Twiki from the docking bay before the flagship is destroyed. On the journey back to Earth, Wilma apologizes to Buck on behalf of the Directorate for misjudging his loyalties.