Morseistakenseriouslyillatamuseumreceptionandishospitalized.Inthehospital,Supt.Strange,visitsMorsetopushhimtotakeearlyretirement,whileDr.Millicent'Millie'VanBurengiveshimherbookona140year-oldcourtcaseknownastheOxfordCanalMurders.Thecaseinvolvedthemurderandrapeofayoungwoman,MrsJoannaFranks,travelingbycanalboatfromCoventrytoLondon.Thecaseresultedinthreeboatmenbeingsentencedtodeathandtwoofthemhanged.MorsestartstoreadMillie'sbookanddreamsaboutit.Hesoonhasanumberofproblemswiththecase.　　Whyweren'tthethreemenalsochargedwiththeft?WhydidMrsFrankstakeaboatinsteadofatrainthatwasmuchfasterandcomfortableandonlyslightlymoreexpensive?Whydidn'tsheabandontheboataftershecomplainedaboutlewdbehaviorofthecrewattheshippingofficeinBanbury?Whydidshethendrinkand'socialise'withthecrew?Whathappenedtoher'carpetbag'withwhichshearrivedontheboatbutwhichwasnotmentionedinthecourtcase,norwasitstoredinthearchiveswithher,almostempty,tru