Summary

In Chapter 4, Ryland continues to explore the ship. He discovers that the Hail Mary is fueled by Astrophage. In a flashback, Ryland performed experiments on the Astrophage in Stratt's lab and discovered it was primarily made of hydrogen and oxygen, a strike against his theory that life does not require water. In the present, he enters the ship's supply room and finds jumpsuits for himself and his two fellow astronauts. He remembers that one was a Russian woman named Olesya Ilyukhina and the other was a Chinese man named Yáo Li-Jie. He dresses their bodies and jettisons them into space through the airlock.

In a flashback, Ryland told his students about the sun's reduced output due to Astrophage and wondered sadly what would happen to them in adulthood if the problem could not be solved. He felt a new commitment to studying...