In Geneva, Dr. Lokken confronts Stratt and Grace, arguing that Hail Mary’s zero-g lab plan is a fatal flaw. After testy debate—including Grace defending panspermia—Lokken proposes a ship-splitting centrifuge using Zylon cables so proven 1g lab gear can be used. Stratt, prioritizing reliability, accepts and drafts Lokken onto the project.

Back in the present, Grace remembers the centrifuge design and finds the control panel. Trusting the engineering, he engages the sequence: the ship halves separate, the crew section rotates 180 degrees, and the system spins up to 1g. The alien ship mirrors his spin, apparently interpreting it as communication.

Grace examines the returned cylinder. It’s intensely hard and surface-tests as xenon, implying an exotic compound he dubs “xenonite.” Inside, he finds two models: a Petrova-line depiction for a star and planet, and a 3D map of nearby stars centered on Tau Ceti, with a link to 40 Eridani. He concludes the aliens likely come from 40 Eridani and are also seeking answers about Astrophage.

To reply, Grace marks Sol on their map and adds a Petrova-line symbol, then spins the ship down and EVA-delivers the modified cylinder back to the aliens, signaling shared stakes and intent to cooperate.

After hours of waiting, a new cylinder arrives. Inside is a model of the Hail Mary and Blip-A connected by a tube to his airlock, clearly proposing a docking tunnel. The aliens want to meet.