To Louise Baltimore and her fellow citizens of Earth in the 99th century, life offers bleak prospects. The world is on its deathbed, dying from the accumulated poisons of one too many wars. Suicide is common, since convincing reasons for hanging around for the planet's final gasps are few.

But there is a plan. Directed by the Big Computer, a group of people are engaged in an all-out effort to create a future for humanity: if not here, then on another planet; if not in their time, then in another, Louise is one of these people. />

Louise is the head of time travel team which uses The Gate to enter the past. There they kidnap people, but not just anyone. Louise must choose only those who are destined to die in their time, passengers of airplanes of the twentieth century that are about to crash, or those involved in similar disasters. They will be rescued and brought to Louise's time, and placed in suspended animation awaiting the moment when a great space/time ship will carry them to a distant planet in an unthinkably distant future. There, these folks, dead in their own time, will give new life to the human race.

The enterprise is risky. In order not to disturb the delicate fabric of time, no shred of evidence must be left, no clue to what happened be allowed to exist. Bloody remains, dismembered bodies, personal effects -- all prefabricated by Louise's people -- are placed in the wrecks to satisfy the curious authorities. For if something should happen to change the flow of time, the timequake that would result could destroy all hope for human survival.

But something has gone wrong. Two stunner guns are lost, one in 1955 and the other in 1980. Three members of Louise's team have already died trying to retrieve them. And now it seems that one of the weapons will fall into the hands of a crash investigator named Bill Smith. And Smith is smart enough to figure out what happened -- and do something about it. Louise must attempt to stop him from changing history. It is a mission of enormous danger. One false move, one tiny mistake, may cause instant disaster. And things don't get any easier when Louise finds herself falling in love with this twentieth-century meddler.

A DC-10 and 747 collide. In the distant future, a time travel team prepares to snatch passengers, leaving prefabricated smoking bodies behind. And an air disaster investigator will get a phone call that changes his life ... and the end of the world as we know it.