Afterbreakingoutofarehabilitationzoo,Frankie,asquirrelwithalltheangles,returnstohisforest.Helearnsfromhisdim-wittedbestfriend,Cody,aporcupineandstreet-con,thatwhilehewasinlock-up,theentireforestwaspickedcleanbyTheA.C.O.R.N.S.Institute(AlternativeCosmeticOilsforRegenerativeNaturalSkin-care).Noacornwasleftbehind.Withwinterjustaroundthecorner,it'sapotentiallydevastatingblowtoallforestcritters.So,Frankiehasnochoicebuttobustintothebrandnew,state-of-the-art,rodent-proofA.C.O.R.N.S.ProcessingPlantandtakebackalloftheacorns!Thoughaseeminglyimpossibleheist,successwouldnotonlysavethelivesofhisforestfriends,butitwouldalsogiveFrankieachancetowinbacktheloveofhislife,Lola,alocalshowsquirrel.Sadly,LolahasbeenburntbytoomanyofFrankie'sfalsepromisesinthepast.WiththesupportofFrankie'soldmentor,Mr.Bellwood,awealthybadger,FrankieandCodyassembleateamoftopnotchcrackersfromallovertheforest,includingabatnamedFlyBoy,atopnotchmunitionsexpert;Raitch,acomputerhackingalbinosnake,whoneverallowsherlackofappendagestogetintheway;Edsyatinyfamilyfrog,whoseabilitytofreezehimselfsolidfordaysonendwithoutharmisinvaluable;agermophobicFrenchratnamedLiam,whocancollapsehisskeletontogetintoanyspace;Chinesefather-daughterpangolinsnamedPangoandLin,thebestdiggersintheforest;andBellwood'shedgehogbutler,Oscarwhoknowshowtogethishandsonanythingthecrewneeds.Withwinterknockingattheirdoor,Frankieandhiscrewhaveonlythreedaystoprepareandexecutethisunprecedentedheist.Whentheylearnthattheprocessingoftheirforest'sacornshasbeenpushedupaday,Lola'srefusaltoparticipateleavesFrankieandhiscrewonecrittershort.Witheverythingontheline,FrankieandhiscrewofAnimalCrackerzsetouttopulloffthebiggestheistinanimalhistory!