Leviathan Falls

Plot summary

After Tiamat's Wrath, the ring entities, sometimes called dark gods, keep testing ways to kill people. They tweak physics in certain systems and launch attacks that make people lose consciousness. Winston Duarte snaps out of his near-catatonic state, suddenly knowing a lot about the Ring-Builders and gaining strange powers, like projecting a mental image of himself into others. He does this to Admiral Trejo, who is busy taking back the Sol system for Laconia.

Duarte thanks Trejo for keeping the Empire alive and says their earlier plans were too small. Then he disappears, so Trejo orders everyone back to Laconia. When they get there, Duarte is gone from the state building. Colonel Aliana Tanaka gets the highest security clearance to find him.

She tracks him to the cave where Amos Burton used to live and figures out Duarte escaped in a small alien ship. To lure him out, she decides to use Teresa Duarte as bait—she fled Laconia with the Rocinante crew in the previous book. Tanaka starts hunting for Teresa by checking on Duarte's relatives in different ring systems. Meanwhile, Elvi Okoye and her team, plus the protomolecule-revived kids Xan and Cara, study the Adro Diamond, a Ring-Builder data storage device.

They use the protomolecule to turn it on, and it talks to Cara through her enhancements, showing her the Ring-Builders' history. Those beings started as sea-slug-like creatures under the ice of a Europa-like moon. They eventually shed their physical forms and became a hive mind that could communicate faster than light. Some of what Cara experiences leaks into Amos, who has similar alterations.