MorseistakenseriouslyillatamuseumreceptionandishospitalizedInthehospital,SuptStrange,visitsMorsetopushhimtotakeearlyretirement,whileDrMillicent'Millie'VanBurengiveshimherbookona140yearoldcourtcaseknownastheOxfordCanalMurdersThecaseinvolvedthemurderandrapeofayoungwoman,MrsJoannaFranks,travelingbycanalboatfromCoventrytoLondonThecaseresultedinthreeboatmenbeingsentencedtodeathandtwoofthemhangedMorsestartstoreadMillie'sbookanddreamsaboutitHesoonhasanumberofproblemswiththecase
　　Whyweren'tthethreemenalsochargedwiththeftWhydidMrsFrankstakeaboatinsteadofatrainthatwasmuchfasterandcomfortableandonlyslightlymoreexpensiveWhydidn'tsheabandontheboataftershecomplainedaboutlewdbehaviorofthecrewattheshippingofficeinBanburyWhydidshethendrinkand'socialise'withthecrewWhathappenedtoher'carpetbag'withwhichshearrivedontheboatbutwhichwasnotmentionedinthecourtcase,norwasitstoredinthearchiveswithher,almostempty,trunkThetrunkwasmarkedwithinitialsofherfirsthusbandwhohaddiedHowdidithappenthathershoeswerefoundontheboatbutnobodysawherreturntotheboatfromtheforest
　　PCAdrianKershawdoessomebrilliantlegworkforMorseHestudiedhistoryandhasinvaluablebackgroundknowledgeForinstance,hementionsthattheboatmenhadbadreputationbecausetheyworkedonSundaysanddidnotattendchurchLaterachapelwasbuiltfortheminOxford
　　Thedeadwoman'sclothesandtheshoesfoundontheboataresubmittedtomodernforensicinvestigationTheresultisthattheshoesdidnotbelongtothedeadwomanfoundinthewaterbecauseshewasmuchtallerTheshoeswereneverusedintheforest
　　OnlyMrsFranks'husband,CharlesFranks,wascalledtoidentifythebodyofthedeadwomanHeclaimedthat,whileherfacewasdarkenedanddisfigured,hefoundabirthmarkbehindherearTheprosecutorwelcomedthatinformation"thatonlyahusbandoraloverwouldknow"TheaccusedwerenotshownthebodyThedefenseattorneymerelyclaimedthattheguiltofthethreemenwasnotprovedAllthreeaccusedclaimedtotheendthattheywereinnocentOneofthemwasnotexecutedbecauseheembracedChristianityinprison
　　MorseinstructsKershawtoinvestigateifCharlesFranksbenefitedfromhiswife'sdeathand,indeed,hepocketed300poundsinsurancemoneyCaseclosed:CharlesFranksmurderedatallwomenanddroppedherinthecanalaftermeetingJoannaintheforestIfJoannaFranksjumpedofftheboatatthesametimeasthedeadbodyhitthewater,sheswamtothebankandjoinedherhusbandThecouplechangedtheirnames,inthecaseof'CharlesFranks'asecondtimeafterhe'died'asJoanna'sfirsthusbandThefourthboatman,ayoungsterwhowasnotcharged,wasprobablypaidbyJoannatogivefalsetestimony
　　MorsetravelstoIrelandandhasagraveofJoanna'sfirsthusbandexhumedThecoffincontainsbagsofsandandsomestones