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
Frederick I, Holy Roman Emperor from the donkey. To add to this debasement, they were made to announce, ""Ecco la fica"" (meaning "behold the fig"), with the feces still in their mouths. It used to be said that the insulting gesture, (called fico), of holding one's fist with the thumb in between the middle and forefinger came by its origin from this event. Frederick's first marriage, to Adelheid of Vohburg, did not produce any children and was annulled. From his second marriage, to Beatrice of Burgundy, he had the following children: Frederick I, Holy Roman Emperor Frederick I (, ; 1122 – 10 June 1190),