A U.S. passenger airliner finds itself on the brink of disaster in 1989, as it faces an imminent collision with another aircraft attempting to land. As the pilot attempts to maintain control of the aircraft, the flight engineer rushes into the cockpit, panic-stricken, exclaiming, "They're dead! All of them! They're burned up!" This shocking announcement propels the narrative into a complex investigation led by Bill Smith, a dedicated investigator from the National Transportation Safety Board. His task is to uncover whether mechanical failures or pilot errors contributed to the tragic crash of both planes.
As the investigation unfolds, Smith and his team grapple with the peculiar comments from the flight engineer recorded in the cockpit, especially since there is no evidence of fire prior to the crash. Meanwhile, a theoretical physicist, Dr. Arnold Mayer, captivates his audience with radical theories about time travel, hinting at a startling possibility: visitors from the future are abducting individuals from planes destined for destruction, to ensure the survival of humanity in an era plagued by pollution and infertility.
In a dystopian future, the human population can no longer reproduce, prompting time travel teams to venture back to the past and extract individuals who are fated to die. These abducted souls are kept in stasis until the time is right for them to help repopulate a ravaged Earth. Most of the abductees in this scenario are in poor health, yet some can convincingly masquerade as beings from the 20th century, often donning replicas of contemporary attire to blend in seamlessly.
Every time a past incursion occurs, it triggers a “timequake,” the intensity of which corresponds to the disruption caused by the abductions. This explains the flight engineer’s bewildering remark: the passengers were not merely dead—we learn they were replaced with duplicates who had already experienced their fiery fate.
A pivotal moment occurs during a mission to 1963, when a time agent faces imminent danger aboard a flight, leading to a critical weapon falling into Dr. Mayer's hands. This chance encounter sets off a chain of events that changes everything for Bill Smith and Mayer. In an attempt to thwart their investigative endeavors and secure the future, Louise Baltimore is dispatched back to 1989, where she skillfully gains Bill's trust through seduction, resulting in an unexpected pregnancy.
As the time travel team's blunders continue to mount, Bill becomes increasingly suspicious, prompting him to approach Dr. Mayer for answers. To their astonishment, Louise reappears from the future, unveiling the mission she's been on. Tragedy strikes when a mishap with Mayer's stun weapon leads to his untimely death, creating an unalterable paradox. This "force infinity timequake" threatens to unravel the very fabric of the civilization in the present timeline.
Realizing the urgency of the situation, the team scrambles to send the abducted individuals to the distant future before their escape route—the Gate—permanently collapses. In a desperate move, Louise and Bill step through the Gate together, embarking on a new chapter designed to secure their survival and ultimate goal of repopulating Earth. Just as a cataclysmic explosion obliterates the Gate, a robot named Sherman reverberates Winston Churchill's famous declaration: "This is not the end. This is not the beginning of the end. It is the end of the beginning."
