Wrath of the Triple Goddess is the second book in The Senior Year Adventures series, seventh in the Percy Jackson and the Olympians series, and 17th in Rick Riordan’s Percy Jackson universe, which includes the series Heroes of Olympus and Trials of Apollo. While Percy Jackson and the Olympians focuses primarily on Greek gods and heroes, the latter two series also incorporate Roman mythology and history. The Senior Year Adventures falls between the end of the Heroes of Olympus, which is set during protagonist Percy Jackson’s junior year of high school, and The Trials of Apollo, which is set when Percy is enrolled at New Rome University (a university in “New Rome,” a fictional California city of demigods and other supernatural beings). The new series bridges a time gap between the two latter series, filling in Percy’s experiences in his senior year of high school and explaining how he achieved his entry into New Rome.

The Burning Maze, the third installment in the series The Trials of Apollo, features the death of a beloved character from the Heroes of Olympus, son of Jupiter Jason Grace. The loss of a main character was a new phenomenon that received a mixed reaction from fans because it featured heartbreak that fans had not come to expect from Riordan.