The Cat in the Hat tells the story of Horton, an elephant who discovers a speck of dust that contains the Whos, including Jojo, a Who child sent off to miltary school for thinking too many 'thinks.' Horton faces a double challenge: not only must he protect the Whos from a world of naysayers and dangers, but he must guard an abandoned egg, left in his care by the irresponsible Mayzie La Bird.