dhimenterthefrontroomonthesecondfloor,generallyusedashissitting-room.Shehadlitafirethere,andasitsmokedshehadopenedthewindow.Nosoundwasheardfromtheroomuntileleven-twenty,thehourofthereturnofLadyMaynoothandherdaughter.Desiringtosaygood-night,sheattemptedtoenterherson’sroom.Thedoorwaslockedontheinside,andnoanswercouldbegottotheircriesandknocking.Helpwasobtained,andthedoorforced.Theunfortunateyoungmanwasfoundlyingnearthetable.Hisheadhadbeenhorriblymutilatedbyanexpandingrevolverbullet,butnoweaponofanysortwastobefoundintheroom.Onthetablelaytwobanknotesfortenpoundseachandseventeenpoundsteninsilverandgold,themoneyarrangedinlittlepilesofvaryingamount.Thereweresomefiguresalsouponasheetofpaper,withthenamesofsomeclubfriendsoppositetothem,fromwhichitwasconjecturedthatbeforehisdeathhewasendeavouringtomakeouthislossesorwinningsatcards.
Aminuteexaminationofthecircumstancesservedonlytomakethecasemorecomplex.Inthefirstplace,noreasoncouldbegivenwhytheyoungmanshouldhavefastenedthedoorupontheinside.Therewasthepossibilitythatthemurdererhaddonethis,andhadafterwardsescapedbythewindow.Thedropwasatleasttwentyfeet,however,andabedofcrocusesinfullbloomlaybeneath.Neithertheflowersnortheearthshowedanysignofhavingbeendisturbed,norwerethereanymarksuponthenarrowstripofgrasswhichseparatedthehousefromtheroad.Apparently,therefore,itwastheyoungmanhimselfwhohadfastenedthedoor.Buthowdidhecomebyhisdeath?Noonecouldhaveclimbeduptothewindowwithoutleavingtraces.Supposeamanhadfiredthroughthewindow,hewouldindeedbearemarkableshotwhocouldwitharevolverinflictsodeadlyawound.Again,ParkLaneisafrequentedthoroughfarethereisacabstandwithinahundredyardsofthehouse.Noonehadheardashot.Andyettherewasthedeadmanandtheretherevolverbullet,whichhadmushroomedout,assoft-nosedbulletswill,andsoinflictedawoundwhichmusthavecausedinstantaneousdeath.SuchwerethecircumstancesoftheParkLaneMystery,whichwerefurthercomplicatedbyentireabsenceofmotive,since,asIhavesaid,youngAdairwasnotknowntohaveanyenemy,andnoattempthadbeenmadetoremovethemoneyorvaluablesintheroom.
AlldayIturnedthesefactsoverinmymind,endeavouringtohituponsometheorywhichcouldreconcilethemall,andtofindthatlineofleastresistancewhichmypoorfriendhaddeclaredtobethestarting-pointofeveryinvestigation.IconfessthatImadelittleprogress.IntheeveningIstrolledacrossthePark,andfoundmyselfaboutsixo’clockattheOxfordStreetendofParkLane.Agroupofloafersuponthepavements,allstaringupataparticularwindow,directedmetothehousewhichIhadcometosee.Atall,thinmanwithcolouredglasses,whomIstronglysuspectedofbeingaplain-clothesdetective,waspointingoutsometheoryofhisown,whiletheotherscrowdedroundtolistentowhathesaid.IgotasnearhimasIcould,buthisobservationsseemedtometobeabsurd,soIwithdrewagaininsomedisgust.AsIdidsoIstruckagainstanelderly,deformedman,whohadbeenbehindme,andIknockeddownseveralbookswhichhewascarrying.IrememberthatasIpickedthemup,Iobservedthetitleofoneofthem,TheOriginofTreeWorship,anditstruckmethatthefellowmustbesomepoorbibliophile,who,eitherasatradeorasahobby,wasacollectorofobscurevolumes.Iendeavouredtoapologizefortheaccident,butitwasevidentthatthesebookswhichIhadsounfortunatelymaltreatedwereverypreciousobjectsintheeyesoftheirowner.Withasnarlofcontemptheturneduponhisheel,andIsawhiscurvedbackandwhiteside-whiskersdisappearamongthethrong.
MyobservationsofNo.427,ParkLanedidlittletoclearuptheprobleminwhichIwasinterested.Thehousewasseparatedfromthestreetbyalowwallandrailing,thewholenotmorethanfivefeethigh.Itwasperfectlyeasy,therefore,foranyonetogetintothegarden,butthewindowwasentirelyinaccessible,sincetherewasnowaterpipeoranythingwhichcouldhelpthemostactivemantoclimbit.Morepuzzledthanever,IretracedmystepstoKensington.Ihadnotbeeninmystudyfiveminuteswhenthemaidenteredtosaythatapersondesiredtoseeme.Tomyastonishmentitwasnoneotherthanmystrangeoldbookcollector,hissharp,wizenedfacepeeringoutfromaframeofwhitehair,andhispreciousvolumes,adozenofthematleast,wedgedunderhisrightar