SummerPrattisrecentlyengagedtoClint,andshecouldn'tbehappier.AsurpriseengagementpartyintroduceshertotheWalshcouple--Clint'sboss,Travis,iswealthyandhandsome.BubblyMrs.Walsh,ablondenamedLily,ishappytohostthesoireeandindulgesalotinwineandchampagne.Summerisaninteriordesigner,andLilyimmediatelyaskshertomakeovertheirsittingroom.Whiletakingmeasurements,Summergetstomeetthemysteriousdaughter,Sophie.Thenannysuddenlyquits,soLilydesperatelyasksSummertofillinuntiltheycanhireareplacement.CaringforSophieispeculiar--shetalkstoaninvisiblefriend,mostlykeepstoherself,andherparentskeepchangingtheirstoriesaboutwhatiswrongwiththegirl.Neitherparentseemsoverlyinvolvedorlovingofthegirl,thoughLilycertainlyseemstotryhardertokeepthegirlunderwrapsandbehavingproperly.Summergraduallygrowsmoresuspiciousoftheentirefamily,andsoonrealizesthatnoneofthethreearetrulywhattheyseemtobe.HerattempttorescueSophiefromwhatshebelievestobeanabusivesituationendsupputtingthechildinmoredangerasawomanfromthepaststepsintofinallydestroythefamily.Summernowhastofacetheconsequencesofherownsnoopingasshetriestosavewhat'sleftoftheWalshfamily.