The trogs lead the demigods to the River Acheron where the nymph Gorgyra agrees to help them in exchange for Nico and Will sharing their story with her. Nico reveals that he had encountered Nyx while traveling through Tartarus before getting captured by the giants and she took an interest in him, realizing that Nyx is using Bob as bait to get at Nico. Pleased with their success, Menoetes reveals that Bob, while reforming from dying while helping Percy and Annabeth, was captured by the primordial goddess of night, Nyx, who seeks to force Bob to go back to being Iapetus despite Bob's continuous rejection of his past. Although the heist is successful, Will encounters the goddess herself who offers him advice on his struggles to understand Nico, suggesting that Will embrace his own inner darkness rather than rejecting it. Nico and Will seek out the help of the troglodytes who agree to lead them to a shortcut to Tartarus, but they must first pass the farm of Menoetes who only agrees not to tell Hades in exchange for fruit stolen from Persephone's garden. Making their way into the Underworld through the Door of Orpheus, which Nico and Percy had previously used, the two demigods are immediately set upon by the demon of nightmares, Epiales, who reveals that their mother is after Nico before Will manages to kill the demon using his newly-discovered power to emit rays of light. Before departing, the two contact Percy Jackson and Annabeth Chase for advice based upon their own experience in Tartarus. Concerned that Bob's situation must be getting more dire, Nico convinces a reluctant Chiron to issue them an official quest. Two months after the defeat of Nero and Python, Rachel Elizabeth Dare provides the prophecy for Nico di Angelo and his boyfriend Will Solace's quest into Tartarus to rescue the Titan Iapetus, better known as Bob, for the twelfth time. A standalone follow-up to the 2020 novel The Tower of Nero, it released in North America and the United Kingdom on May 2, 2023, and was published by Hachette Books. The Sun and the Star is a fantasy novel co-written by authors Rick Riordan and Mark Oshiro.

The Ship of the Dead by Rick Riordan