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