Protecting the ancient Jedi Kyber Crystal Temple on Jedha was a spiritual and grueling task for two Guardians of the Whills named Chirrut Îmwe and Baze Malbus. A new Star Wars novel will depict exactly what Chirrut and Baze went through after their sacred task was up-ended by the occupation of the Empire.

Written by well-known comic book scribe Greg Rucka, Guardians of the Whills is a middle-grade novel which will explain exactly what Baze and Chirrut’s relationship was with Saw Gerrera and other extremist Rebels on Jedha prior to their meeting Jyn and Cassian in Rogue One. In the film, Chirrut mentions that Baze was the most “devoted Guardian,” prior to the Empire’s insurgence. What Chirrut meant by this could be revealed in this new book along with additional information about what the hierarchy between the Guardians of the Whills and the Jedi Knights actually looked like.

Taken from an old George Lucas concept, the notion of the “Whills” was originally going to refer to immortal beings who narrated the entirety of Star Wars. Though Lucas eventually “dropped” the idea, the word was rejiggered in Rogue One to describe Chirrut and Baze’s former occupation.

Along with the Jyn Erso YA novel Rebel Rising, Guardians of the Whills will be published by Disney Books on May 2, 2017.