The asteroid Eros clearly has developed a mind of its own. It hurtles through space — toward Earth — with Miller hanging on for dear life, with a nuke he intends to detonate in a heat source that Rocinante crew member Naomi believes to be controlling the asteroid.
The United Nations military brain-trust naturally freaks out and fires 150 nukes at Eros, but the asteroid cloaks itself from radar, leaving the missiles "blind" to its presence.
Through nervous, time-delayed exchanges, the U.N., Fred Johnson and Capt. Holden agree to a plan: the Rocinante will follow Eros within visual range and guide by laser, Earth's missiles, to destroy Eros. The Rocinante crew puts itself in peril by accelerating to a high-G burn to keep up with Eros' pace.
While Miller proceeds, he hears voices — ones Naomi thinks are from the people who Protomolecule struck dead. Miller follows the voices toward the Blue Falcon hotel, where he and the Rocinante crew originally found Julie Mao's Protomolecule-ridden body.
He hears a voice say the word "Razorback," which he recognizes as the name of the ship she traveled on, to reach Eros. Miller tells Naomi he thinks Julie somehow "infected" Protomolecule, when it infected her, syncing the two living organisms.
Sure enough, Miller finds Julie's body "plugged in" to Protomolecule, with tubes connecting her and it. Miller awakens her with conversation.
Julie, minus the barnacles she had when first infected, asks where she is and what she's doing. She says she can't help steering the asteroid toward Earth, because she misses her home planet.
Miller takes off his helmet and protective gear. He persuades Julie to crash Eros into Venus, but before the explosive impact, he professes his love to her and they passionately kiss.