<P> The book continues the story of Apollo as the mortal Lester, as he leaves the safety of Camp Half - Blood and journeys across North America to restore the remaining four Oracles and defeat the triumvirate of Roman emperors - turned - Gods, while also being helped by Leo Valdez, the now - mortal Calypso and Festus the bronze dragon . </P> <P> The Burning Maze is the third book in the series . It released on May 1, 2018 . The book follows Lester Papadopoulos / Apollo, Meg McCaffrey and Grover Underwood while they try to rescue Herophile, an Oracle that speaks only in puzzles, from the Roman emperor Caligula and his talking horse, Incitatus . In the process, they meet some strixes that fed only on blood . They are repelled using strawberries . While sleeping, Apollo dreams about Herophile telling him that he must save her even though it's a trap . When he wakes up, he finds himself in Grover's base . When Meg wakes up, they find the line from the prophecy,' Demeter's daughter finds her ancient roots' to occur . Apollo and Grover go out to try to find Gleeson Hedge in an army store called Macro's Military Madness . They then find out that Macro, the store owner is actually Naevius Sutorius Macro, working for Caligula . He attacks them with an army of automatons . By activating' command sequence: Daedalus twenty three', they defeat Macro with his own robots . They then navigate the maze with the help of Piper McLean and Jason Grace and find defeat Medea, the sorceress who was working with the emperor . During the battle, Jason dies . The next day, Grover, Meg and Apollo using Caligula's shoes walk the Labyrinth . </P> <P> The Tyrant's Tomb is the fourth book in the series . It will be released on Fall 2019 . </P> <P> A companion book titled Percy Jackson: Camp Half - Blood Confidential was released on May 2, 2017 . </P>

When does trials of apollo 4 come out