With the ships reconnected and back in zero g, Ryland Grace and Rocky continue breeding nitrogen‑tolerant Taumoeba. They reach Taumoeba‑35 and press on toward the 8 percent nitrogen goal needed for Venus and Threeworld. Rocky builds an Earth‑power and life‑support enclosure to preserve a human laptop for Eridian scholars, while Grace requests xenonite samples for Earth.

Grace undertakes exhaustive EVAs to purge Taumoeba contamination from the Hail Mary’s fuel bays, using an Eridian cutting torch and nitrogen sterilization. Two bays remain infected; one (Fuel Bay Five) proves impossible to sterilize and is jettisoned. Short on storage, Grace calculates he can’t get home with available food at reduced acceleration. Rocky insists on rest and then fabricates three replacement fuel bays from “metal stew.”

After a grueling installation EVA, Grace mounts the new tanks. Meanwhile, Taumoeba generations advance to Taumoeba‑78, then culminate in Taumoeba‑80 and Taumoeba‑82.5, which survive and thrive in precisely simulated Venus and Threeworld atmospheres. They plan rigorous testing and redundant backups.

They celebrate: Grace finds vodka in Ilyukhina’s kit; Rocky dons ceremonial clothing. Grace requests tiny, long‑duration Taumoeba life‑support “farms” for the beetles; Rocky agrees and also completes a fuel‑transfer system. The Hail Mary is refueled to 2.2 million kilograms, exceeding its original load.

Final preparations follow: both ships secure multiple independent Taumoeba‑82.5 colonies; Rocky departs with a laptop in a protective enclosure; the Hail Mary retains xenonite tunnels for future study. After reviewing relativistic timelines, the friends share an emotional farewell. Rocky accelerates home to Erid; Grace sets course for Earth and ignites the spin drives.