Theodora, Sherman, and Dexter are off to the Big Pumpkin for the holidays, and they cannot wait! However, if Dracula and Mummy thought an overseas trip would keep Theodora safe from bad monsters with sinister intentions, they were wrong. For New York is teeming with Shadowmongers--sly, shadowy creatures controlled by the most sinister foe of all. A foe who wants nothing more than to see the Monstrous League of Monsters brought down...and Theodora with it.