Thor, the Norse god of thunder, is worse than a blowhard and a bully—he’s ruined countless lives and killed scores of innocents. After centuries, Viking vampire Leif Helgarson is ready to get his vengeance, and he’s asked his friend Atticus O’Sullivan, the last of the Druids, to help take down this Norse nightmare.

Over the next two decades, Geisel concocted such delightfully loopy tales as The 500 Hats of Bartholomew Cubbins and Horton Hears a Who. Most of his books earned excellent reviews, and three received Caldecott Honor Awards. But it was the 1957 publication of The Cat in the Hat that catapulted Geisel to celebrity.