As an autistic scholarship student at the prestigious Webber Academy in New York City, Waverly is used to masking to fit in. So when her tutoring student and resident 'it girl' asks Waverly to attend the school's annual Masquerade disguised as her, Waverly jumps at the chance - especially once she finds out that Ash, the dean's daughter and her secret ex-girlfriend, will be there. The Masquerade is everything Waverly dreamed of. Most importantly, there's Ash. All Waverly wants to do is shed her mask and be with her, but the evening takes a sinister turn when Waverly stumbles into a secret meeting between the dean and the school's top donors - and witnesses a brutal murder. Waverly's fairy-tale has turned into a nightmare, and she, Ash, and her friends must navigate through a dizzying maze of freight elevators and secret passageways if they're going to survive the night.