Project Hail Mary: A Novel
Andy Weir
Ryland Grace and Rocky successfully breed Taumoeba-82.5, a strain that survives both Venus-level and Threeworld-level nitrogen concentrations, completing their core mission. After refueling the Hail Mary with Rocky's Astrophage and exchanging parting gifts — a laptop loaded with human knowledge for Rocky, xenonite samples for Earth — they say a tearful goodbye and launch for their respective home systems. A flashback to Baikonur shows Stratt explaining to a captive Grace why she condemned him to a suicide mission: without the Hail Mary, Astrophage means war, famine, plague, and civilizational collapse.
- Taumoeba breeding used 10 tanks with incremental nitrogen percentages each generation; Tank Three was Grace's lucky tank; Taumoeba-82.5 (surviving 8%+ nitrogen) was confirmed in Tanks Nine and Ten after 82+ generations.
- Fuel bay problems: two bays couldn't be fully sterilized and one had to be jettisoned, leaving Grace short on fuel storage and facing a 5.5-year trip home with insufficient food — Rocky solved this by fabricating three replacement bays from Blip-A scrap metal.
- Rocky built a life-support enclosure for a laptop loaded with human knowledge (effectively all of Wikipedia), including a camera-to-texture converter so Eridians can read it; Grace requested xenonite samples in return.
- Grace installed mini Taumoeba farms on each beetle as redundant backups, and Rocky set up six redundant Taumoeba-82.5 colonies on the Blip-A for Erid.
- The goodbye scene: Rocky wore ceremonial Eridian dress; Grace drank Ilyukhina's vodka; both acknowledged they will likely never meet again given human lifespan limits, though Rocky suggested future interstellar visits once Astrophage technology matures.
- Stratt's Baikonur flashback explains her reasoning: without a solution, Astrophage triggers food collapse, then wars fought over farmland, then plague — 'War, famine, pestilence, and death' — making any sacrifice for the mission justified in her view.
Where you left off: Grace has just fired up the Hail Mary's spin drives and set course for Earth, with a fragmented final thought cutting off mid-sentence as she reflects on returning to confront Stratt.