Psychiatrist John Donelly is treating Laura, a woman who claims to have been left on Earth by the alien Holock. She claims that she has only one year to convince one person—anyone—that her story is true, or she will have to leave Earth. She says that the Holock take great interest in earthly affairs because entering human dreams is their primary form of entertainment. Donelly believes her story is an elaborate delusion, until strange events—and even stranger dreams—invade his mundane existence. His dreams become more vivid, each of them featuring the same ten-year-old boy. One of his colleagues is murdered the same night that Laura strikes him after he tells her he does not believe her. A detective investigating the murder tells Donelly that a Vietnamese soldier he killed during the Vietnam War has begun appearing in his dreams, asking him about Laura and the Holock.
Donelly meets Saul, Laura’s former “guardian angel” and the unwitting progenitor of the Holock. Saul reveals that the Holock come not from space, but from Earth’s own post-holocaust future, and that they devour dreams, preventing humanity’s ethical evolution to ensure their own eventual creation. He also says that Donelly’s child will be the savior of the human race. Donelly sleeps with Laura, who soon reveals her pregnancy and allegiance to the Holock, then disappears into the future.
To set things right, Donelly asks to use Saul’s time machine. This device induces a form of mental time travel that not only causes users to “blip” back and forth throughout their own lifetimes, but generates changes that ripple out into both the past and the future. Donelly soon finds himself on the run from government agents, who have made a deal with the Holock. He eventually tracks down Laura in the future, only to find her living with an alternate version of himself, the self that really slept with Laura, the one he finally agrees to kill in order to save the world and usher in a new golden age, free of the Holock.