In a world where meat means survival, Frank can't seem to catch a break—or an animal. He just can't bring himself to kill a fellow creature. Just looking into a baby mammoth's big eyes is enough to turn him vegetarian. But while out looking for fruit to eat, he runs afoul of an old nemesis: the wily Leonard, who once stole his Swiss Army knife (and is still puzzling over it). Will Frank's new mammoth friend save him from Leonard's clutches? Will Leonard save them all from the common cold? And just why is their forbidden fruit forbidden?