In The Terrible Two, a middle-grade novel due from Abrams/Amulet in January 2015, authors Mac Barnett and Jory John introduce two rivals for the title of best prankster in town who finally decide to team up to pull off a gigantic prank. Amulet will publish in January 2015 with a 500,000-copy first printing. In keeping with the book’s premise, Barnett and John trotted out their own pranks this Wednesday, when they revealed the cover, created by illustrator Kevin Cornell, to a group of 400 third- to eighth-graders at the Mary Collins School in Cherry Valley, Calif. The gag? The two removed a sheet from an easel to reveal a faux cover: a photo of the school librarian, complete with doodled facial hair.

Barnett reflected on the fanfare surrounding The Terrible Two’s live cover reveal –– and was duly remorseful about the initial snafu. “Tweeting out a jpeg is all well and good, but to us it’s not a cover reveal unless you wheel out a big easel, get the school band to give you a drumroll, and pull back the curtain to reveal a giant blow-up of the novel's cover while kids cheer and applaud,” he said. “Also, we’d like to apologize to school librarian April Derby for at one point accidentally revealing a giant photograph of her with a goatee drawn on her face, and we promise we will not rest until the pranksters responsible are brought to justice.”

But Barnett and John didn’t stop with the cover hoax. Riffing off the novel’s opening prank, which involves someone purloining the principal’s car and using it to block an entrance to the school, the two arranged for the Mary Collins School principal’s sedan to appear mysteriously in the playground. “The kids loved the total concept – the prank cover, and then the real cover, and they are still jazzed about the big prank of the afternoon, when Mac and Jory snagged the principal’s car,” reported Patty Norman, children’s events specialist at Copperfield’s Books in Petaluma, Calif., who coordinated the event.

And might the premise of The Terrible Two be inspired by the authors’ own experiences? Sort of, acknowledged Barnett: “Jory and I have been friends for 10 years, and we've spent much of that time pranking each other. We thought it might be more productive to write some books together.”