The Trials of Apollo Audiobook series is a pentalogy of fantasy adventure and mythological fiction audiobooks written by American author Rick Riordan that collectively form a sequel to the Heroes of Olympus series. It is set in the same world as other Riordan tales, and references characters and happenings from earlier series.
During his tour for The Sword of Summer, Riordan announced his next project, a five-part series about the god Apollo.
The series will be about how Apollo has been turned into a human because Zeus is angry with him. He becomes a 16-year-old mortal boy in New York City with absolutely no powers. He has a lot of enemies and only a few friends – friends who spend their time at Camp Half-Blood.
Riordan referred to this series as “the capstone on Percy Jackson’s world”, so that by the end of it, all of the major characters from both previous series would be revisited.
The first audiobook in the series, The Hidden Oracle Audiobook, was released on May 3, 2016. The second audiobook in the series, The Dark Prophecy Audiobook, was released on May 2, 2017. The third audiobook in the series, The Burning Maze Audiobook, was released on May 1, 2018. The fourth audiobook in the series, The Tyrant’s Tomb Audiobook will be released in October 2019.