The Purple Grumblies are terrified when they hear that Percy the Dreaded Sea-Monster is headed towards their Grumblie Island.They escape to nearby Volcano Island over shark-infested waters by using their upturned umbrellas as sailboats. Thanks to the Pixiecats, small Meerkat-like animals who live in the sand on Volcano Island, they hide inside the volcano just as Percy arrives. Hungry Percy climbs to the top of the volcano and peers inside; he knows they’re in there somewhere. He can SMELL them! But the Grumblies out-smart him.