Captain Underpants's spookiest--and stretchiest--adventure yet! George Beard and Harold Hutchins are back in a new Halloween adventure! Piqua's biggest pranksters are getting ready for the best holiday ever--Halloween, of course. But their dreams of costumes, candy, and haunted houses go down the drain when Mr. Krupp and Melvin start a campaign to make Halloween illegal! That's when George and Harold come up with HACK-A-WEEN, a totally legal spin-off of Halloween. But will disguises, hack-o'-lanterns, and sneak or snacking fill the pumpkin-shaped holes in their lives?