Noah'sarkdriftsontheopenseas，withbestfriendsFinnyandLeahonboard.But，afterweekswithnolandinsight，foodstocksarerunninglow.Thefragilepeacebetweencarnivoresandherbivorescouldbreakanysecond.Afteraseriesofunfortunateevents，thekidsfindthemselvesinadvertentlywashedoverboard-alongwiththelastofthefoodsupplies.Leahandfellowcastaway，theirnewfriendJelly，aremaroonedonaremoteisland.WhileFinnywakesinastrangecolonyfilledwithoddlyfamiliarcreatureslivinginharmony-underthethreatofamenacingvolcano.Inaraceagainsttime，tideandterrifyingtremors，Finnymustrescuehisfriends，reunitewithhisfamilyandsaveawholecolonyfromtotaldestruction。