The autistic son of Sofia Mendes Quinn and her husband Jimmy Quinn, who dies before the birth in 2042, Isaac cannot stand the chaos in which he is raised among the Runa of the planet Rakhat as they evade the Juna'ata, who hunt them for their meat. Isaac is obsessed with an antique hand-held computer and the sounds of music in his head. Isaac sometimes uses real speech, but this opens him to outside menaces, particularly red light and the noise of Runa children playing. Sofia thinks he will be better off returning to Earth aboard a ship free of surprises and surrounded by music. Heading for the lander, Isaac for the first time finds himself exposed to the unfiltered red light of the smallest sun, which wreaks havoc with his senses. Hearing the Sh'ma chanted gradually calms him.