The North American Companion, Da'an, arrives at a Midwestern town. William Boone, a local police captain, is prevented from implementing security arrangements for Da'an, by Special Agent Ronald Sandoval, an implant.
In short order, Da'an arrives in an insectlike shuttle, flown by Marine pilot Lili Marquette. He announces a new alliance between Doors International, a huge corporation, and the Taelons, aliens who arrived on Earth and eradicated various problems such as hunger and some diseases. While Da'an makes a speech to the assembled crowd, a man in a nearby building aims a gun and fires, but billionaire Jonathan Doors takes the bullet, and dies despite the best efforts of Marquette and Doctor Julianne Belman.
Sandoval uses a sluglike creature attached to his arm to fire an energy blast, but the sniper escapes. Boone chases the man down, but loses him after recognizing him as Eddie Jordon, a very old friend. The Taelons declare Boone a hero, and Da'an offers to make him the Commander of Interspecies Relations. Boone declines, hoping to settle down with his wife, Kate. When Sandoval pushes the offer, Da'an interjects with the statement that he hopes Boone will change his mind, but that he accepts the decision.
After ordering his partner to bring Jordon to him first if he's caught, Boone speaks to his wife, who urges him to work for the Taelons, then accepts that he won't. Marquette meets Jordon in a bar, and they talk about Boone.
But as Kate Boone drives home, a man pursues her and forces her car to weave dangerously, until it explodes. As Boone grieves for his wife, he is pressed by the mayor to accept Da'an's offer. He accepts it, but afterwards is approached by Lili Marquette. She leads him to a colorful bar called the Flat Planet Cafe, where the very-much alive Jonathan Doors is in hiding. They, along with Doctor Belman, are part of an anti-Taelon movement called the Resistance. They distrust the Taelons, and seek to uncover a sinister plot.
If Boone became Da'an's implant, a half-germ, half-computer chipp will be implanted in his brain--a CVI. The CVI saps away all free will and directs the person's actions to work for the interests of the Taelons. Belman offers to alter Boone's CVI so that the motivational imperative will be non-functional. Boone agrees to join them.
The next day, Boone is implanted, using a long needle that injects the CVI into his brain while Da'an watches. Afterwards, Sandoval and Da'an give Boone his skrill, which digs into his arm and becomes an appendage of his nervous system, able to fire energy blasts.
Boone and Sandoval are immediately called away, to where Eddie Jordon's body has been found. Not certain who has killed his friend, Boone grimly agrees with Sandoval that he needs to pick his friends carefully.
