AyounggirlcalledAnnetjeLieisstayingwithhergrandmotherforanundisclosedperiodafterherfatherunceremoniouslydroppedheroffandleft.Atnight,AnnetjedisappearsintoadreamworldinwhichherfriendtheMoontransportsherbacktoherelderlyhome.ThereshegetsintoallsortsofnightmarishadventureswiththeKingofMiceandthemysteriousHeintjeVaar.Meanwhile,hergrandmotherisbeginningtosuspectAnnetjemightbeseriouslyill.