Trapped on a dying Eros, Holden and Miller fought their way through the station's old smuggling tunnels toward the docks, dosed with lethal radiation and racing the clock. Around them the full atrocity revealed itself: the entire population of a hundred thousand people had been deliberately infected with the protomolecule and wired for observation — a live experiment run by the scientist Dresden and his backers, staged to look like a plague that Earth, Mars, and the Belt would each blame on one another, starting a war and burying the truth. They saved a handful of souls, left the treacherous spy Kenzo behind, and reached the Rocinante, where Naomi had refused to leave without them. As the hired Belter mercenaries realized their Earther masters had never meant to let them escape either and rose up in the docks, Alex threw off the ship's disguise and flew his gunship out just as Eros was sealed behind quarantine beacons. Miller, who had chased Julie Mao across the system to find some kind of meaning, finally reached her only to lose her — but in escaping, the crew caught the experiment's data being beamed to a hidden station called Thoth, and with it, a fix on the people behind everything.
Fred Johnson's broadcast had already told the system that the stealth ships were built at Earth's Bush Naval Shipyards. Now, on Earth, Chrisjen Avasarala uncovered how deep the rot ran. Errinwright's people were spinning the evidence to frame Fred Johnson, but Avasarala understood the real shape of it: the ambassador Frank DeGraaf had not killed himself — he had been murdered because he knew the drives were stolen, which pointed the conspiracy back inside Earth's own government. And at the Secretary-General's table she was introduced to one of Earth's trusted defense contractors — Jules-Pierre Mao, Julie's father, the man whose weapon had consumed his own daughter and now an entire station.
When we last left off, the war Earth and Mars had nearly stumbled into stood exposed as the work of a hidden faction wielding an alien weapon on living people. Julie Mao was dead, Eros was a sealed tomb of the infected, and a jaded detective and a reluctant ship's captain — strangers weeks ago — now shared the only proof of what had been done and a single lead pointing toward those responsible.