Felicia Day and Sean Astin are about to hit the shelves — or at least, the streets of an eerie carnival.

The pair will guest-star in the third season of The Librarians in an episode titled “And The Tears of a Clown,” in which the Librarians investigate a mysterious traveling carnival. Astin plays Kirby Goulding, a vengeful magician who has grown frustrated with his skills over time, until he somehow receives the power of real magic, which he uses to find his childhood crush, Charlotte Halloway, played by Day.