Since its debut in 1996, DEXTER'S LAB has been one of Cartoon Network's top-rated shows. Now Scholastic teams up with the boy genius and his pesky sister Dee Dee for original chapter and picture books Dexter goes medieval! He is Sir Dexter of Labalot, a Knight of the Periodic Table, and he must save the fair Lady DeeDeever from a horrible fate. But unfortunately, Dexter's rival, the evil Sir Mandark, has followed him back to days of olde and is constantly getting in the way. Will the squabbling knights be able to put aside their differences and come to Lady DeeDeever's rescue?.