It's officially spread all the way to William McKinley High School, and there's nothing Puck, Artie and Mike can do about it.
We refer, of course, to Justin Bieber Fever.
As teased in the official promo for "Comeback," tomorrow night's new installment will center around Sam's plan to start a tribute band. Why do the aforementioned New Directions member wish to join? What do they want to call the group? Find out in the following clip.