The Trials of Apollo 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. "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 met some strixes that feed only on blood, which they finally repel using strawberries. While sleeping, Apollo
Holy Roman Emperor of Eastern Francia fell within the boundaries of the Holy Roman Empire. The various German princes elected one of their peers as "King of the Germans", after which he would be crowned as emperor by the Pope. After Charles V's coronation, all succeeding emperors were called "elected Emperor" due to the lack of papal coronation, but for all practical purposes, they were simply called "emperors". The term "sacrum" (i.e., "holy") in connection with the German Roman Empire was first used in 1157 under Frederick I Barbarossa. Charles V was the last Holy Roman Emperor to be crowned by the Pope