In August 1943, Pilot Officer Maude Garrett, a female flight officer, is assigned to travel with a top secret package from Auckland, New Zealand, to Samoa. When she arrives at the airbase, she sees a ground crew ramp worker disappear before her eyes-just before suddenly finding herself standing right in front of her transport, a B-17 bomber called The Fool's Errand. The bomber's crew gives her a mostly derisive welcome and she is quartered in the Sperry Ball turret for the takeoff. With no room left for her document valise, she reluctantly allows the only crew member friendly to her, Staff Sergeant Walter Quaid, to store it.While stuck in the turret, Maude sees some sort of creature clinging to the underside of the bomber's wing. She reports it, but most of the crew-except Private Beckell, who sees it too-dismisses her. When she is allowed to leave the turret, the hatch malfunctions, trapping her inside. When she reacts indignantly to the crew's comments about her situation, they abandon their attempts to open the hatch and the comm is cut off. After seeing a Japanese fighter appearing and disappearing close to the bomber, she is abruptly attacked by the creature, a gremlin; she fights it off but ends up injured. When the crew contacts her again to ask what happened, a radio message comes in telling them that a Maude Garrett doesn't exist and is not registered for the flight. When they intend to take her out for questioning, Maude deliberately jams the turret's gears and prepares to defend herself when the Japanese aircraft reappears and attacks. Taking control of the turret, she shoots it down, winning the crew's grudging respect.While continuing to talk with the crew, Maude admits she is actually married and boarded the bomber under her maiden name, but refuses to reveal her mission, citing its secrecy. Then she sees the gremlin again as it continues to sabotage the bomber. Eventually Private Dorn sights it too, but the others disregard him. Suspecting Maude's assignment is the cause of their misfortunes, Reeves gives the order to open the bag, which contains a baby-Maude's and Quaid's extramarital child. Forced to confess, Maude explains that she was severely mistreated by her husband; she has an affair with Quaid and inadvertently got pregnant. Someone betrayed her to her husband, who came to the base. Deciding not to tell Quaid, Maude faked her assignment to get away from her husband, who she says would have killed her in his rage.Just as Captain Reeves turns back to the airbase, three Mitsubishi A6M Zero fighters attack and the gremlin boards the bomber, injures Quaid and kidnaps the baby. When the gremlin appears before her with the baby in the bag, Maude exits the turret and fires her handgun at it, driving it off but leaving the bag hanging precariously from the engine nacelle. Risking a perilous climb, Maude retrieves her child and reboards the aircraft through the opening for the ball turret, which has been shot off. The gremlin attacks again, throwing Technical Sergeant Taggart out of the aircraft before Maude can evict it. When Reeves, Lieutenant Finch and Dorn are killed by Japanese gunfire, Maude takes command and brings the bomber roughly but safely down to the ground. The gremlin reappears and tries to snatch the baby once more but Maude catches up and finally kills it. She and the other survivors watch as The Fool's Errand burns and explodes.(copied from Wikipedia)