It's a whole new ride from master of horror and bestselling author R.L. Stine--with a story so fiendish that it can't be contained to just one book! What should Carly Beth be for Halloween this year? TERRIFIED! Late at night, an ugly green mask is mysteriously calling out to her, and ugly green masks don't like to be ignored. If Carly Beth survives the night, even a scary theme park might sound like a vacation. Or maybe not! At HorrorLand, every night is Halloween. And those monster masks? They aren't masks.