FormerpolicedetectiveAdrianMonk(TonyShalhoub),whosephotographicmemoryandamazingabilitytopiecetogethertinycluesmadehimalocallegend,hassufferedfromintensifiedobsessive-compulsivedisorderandavarietyofphobiassincetheunsolvedmurderofhiswife,Trudy,in1997.NowonpsychiatricleavefromtheSanFranciscoPoliceDepartmentandworkingasafreelancedetective/consultantondifficultcases,Monkhopestoconvincehisformerboss,CaptainLelandStottlemeyer(TedLevine),toallowhimtoreturntotheforce.Stottlemeyer,whowaveredbetweenadmirationforMonkandannoyanceathiseccentricitiesduringthefirstseason,isbecomingmoreofafriendtoMonkastheseriesdevelops,frequentlycallinghimintohelp,asmuchforMonk'sbenefitasforhisown.However,heknowsMonk'slimitationsaswellashisstrengthsandmaystillharbordoubtsaboutthewisdomofallowingMonktocarryagunorsubdueaperpetrator.Stottlemeyer'ssecond-in-command,LieutenantRandallDisher(JasonGray-Stanford),alsoseemstobedevelopingbothadmirationandcompassionforthemanheoncelabeled"thedefectivedetective."　　Despiteflawsandinadequaciesallaround,thethreearebecominganincreasinglyeffectiveteam,withadditionalhelpfromMonk'spersonalassistant.Fromthedouble-episodepilotthroughthefirsthalfofseasonthree,Monkwasaidedbyhisnurse,SharonaFleming(BittySchram).Butinthetenthepisodeofthethirdseason,Sharonawasreplacedbyanewassistant,NatalieTeeger(TraylorHoward).LikeSharona,adivorceewithasonnamedBenjy,Natalieisasingleparent,awidowwithadaughternamedJulie(EmmyClarke).UnlikeSharona,Natalieisnotanursebutaformerbartenderwithafreshperspectiveon"Mr.Monk,"asshestilladdresseshernewboss.