The Audition is a free prequel to Seraphina available online. It takes place a few weeks prior to Seraphina, covering Seraphina Dombegh's audition to become Viridius's assistant and consequently Glisselda's music tutor.
The court musician of Goredd, Viridius, is ill with gout, and requires an assistant. With the dubious moral support of Orma, Seraphina Dombegh manages to surpass twenty-four other candidates and makes it to the final round of Viridius tests along with two other hopefuls. She, a master lutist, and a troubadour are taking the final test: giving the musically disinclined Princess Glisselda her music lesson.
As Seraphina is the last to arrive, she is the last to attempt the test. The master lutist goes first, leaving Seraphina waiting with Orma, the troubadour, and Viridius. Seraphina is distracted by Orma, who, despite giving her a twelve-percent chance of success, is already making a list of books for Seraphina to fetch him from the Queen's private library.
An hour later, the lutist returns, outraged and covered in coal dust. The troubadour is up next, uneasy about what may be ahead. Viridius tells Seraphina that the lutist never even managed to give the Princess her lesson. When Seraphina turns back, she sees that Orma has left. A page boy drops by some time later, telling her that her friend is in trouble.
Seraphina hurries to find him, but runs headlong into a pretty, fifteen-year-old girl standing on a chair endeavoring to balance a bucket of fishy slime on the top ledge of a door. Seraphina realizes that this is Princess Glisselda, who is setting a trap for her third potential music tutor—Seraphina herself, though Glisselda doesn't realize this. Seraphina helps her set up the trap and then plays on Viridius's harpsicord for Glisselda, likening it to Glisselda's favorite thing: statecraft. Reluctantly, Glisselda practices with Seraphina. She's not very talented, but she makes up for it in determination, finally learning her lesson.
Viridius enters with a crash, falling prey to the prank. As the mischievous princess helps the drenched old man off the ground, she accepts Seraphina as her music tutor, revealing she knew Seraphina was the final candidate all along.
As Seraphina leaves, she encounters Orma, who had received a private invitation to the Queen's library—courtesy of Glisselda, in order to lure Seraphina to her—and had spent the whole time reading its books. He had even snuck the book he was reading out of the library by hiding it under his shirt.
Happily, Seraphina departs with her uncle.