”Ican’t。Ihatethefellow。Ihateanyonewhomakesmelookridiculous。He-well，well，ifyou’llhaveit，sir，Iwillsaythismuch。Ifitweren’tforthatblastedcoincidenceofthetwodeathsequallymysterious，equallyunderhiseye，I’dstakemylifeonhishonesty。Butthatcoincidencestumpsmeand-andasortoffeelingIhavehere。”Itistobehopedthattheslaphegavehisbreast，atthispoint，carriedoffsomeofhissuperfluousemotion。”Youcan’taccountforafeeling，Mr。Gryce。Themanhasnoheart。He’sashardasrocks。””Anotuncommonlackwheretheheadplayssobigapart。Wecan’thanghimonanysuchargumentasthat。You’vefoundnoevidenceagainsthim?””N-no。”ThehesitatingadmissionwasonlyaproofofSweetwater’sobstinacy。”Thenlistentothis。Thetestwiththelettersfailed，becausewhathesaidaboutthemwastrue。Theywerenotmeantforhim。
　　MissChallonerhadanotherlover。””Onlyanother?Ithoughttherewereahalf-dozen，atleast。””Anotherwhomshefavoured。Thelettersfoundinherpossession-nottheonesshewroteherself，butthosewhichwerewrittentoheroverthesignature0。B。werenotallfromthesamehand。
　　Expertshavebeenbusywiththemforaweek，andtheirreportsareunanimous。The0。B。whowrotethethreateninglinesacknowledgedtobyOrlandoBrotherson，wasnotthe0。B。whopennedallofthoseloveletters。Thesimilarityinthewritingmisledusatfirst，butoncethedoubtwasraisedbyMr。Challoner’sdiscoveryofanallusioninoneofthemwhichpointedtoanotherwriterthanMr。
　　Brotherson，andexpertshadnodifficultyinreachingthedecisionIhavementioned。””Two0。B。s！Isn’tthatincredible，Mr。Gryce?”
　　Yes，itisincredible；buttheincredibleisnottheimpossible。
　　Themanyou’vebeenshadowingdeniesthattheseexpressiveeffusionsofMissChallonerweremeantforhim。Letussee，then，ifwecanfindthemantheyweremeantfor。””Thesecond0。B。?”
　　Yes。”
　　Sweetwater’sfaceinstantlylitup。”DoyoumeanthatI-aftermyegregiousfailure-amnottobekeptonthedunce’sseat?Thatyouwillgivemethisnewjob?””Yes。Wedon’tknowofabetterman。Itisn’tyourfault，yousaidityourself，thatwatercouldn’tbesqueezedoutofamillstone。””TheSuperintendent-howdoeshefeelaboutit?””Hewasthefirstonetomentionyou。””AndtheInspector?””Isgladtoseeusonanewtack。”
　　Apause，duringwhichtheeagerlightintheyoungdetective’seyecloudedover。Presentlyheremarked：”Howwillthefindingofanother0。B。alterMr。Brotherson’sposition?Hestillwillbetheonepersononthespot，knowntohavecherishedagrievanceagainstthevictimofthismysteriouskilling。Tomymind，thisdiscoveryofamorefavouredrival，bringsinanelementofmotivewhichmayrobourself-reliantfriendofsomeofhiscomplacency。Wemayfurther，ratherthandestroy，ourcaseagainstBrothersonbylocatingasecond0。B。”
　　Mr。Gryce’seyestwinkled。”Thatwon’tmakeyourtaskanymoreirksome，”hesmiled。”TheloopwethusthrowoutisaslikelytocatchBrothersonashisrival。Italldependsuponthesortofmanwefindinthissecond0。B。；andwhether，insomewayunknowntous，hegavehercauseforthesuddenandoverwhelmingrushofdespairwhichalonesupportsthisgeneraltheoryofsuicide。””Theprospectgrowspleasing。WhereamItolookformyman?””YourticketisboughttoDerby，Pennsylvania。Ifheisnotemployedinthegreatfactoriesthere，wedonotknowwheretofindhim。Wehavenootherclew。””Isee。It’sashortjourneyIhavebeforeme。””It’llbringthecolourtoyourcheeks。””Oh，I’mnotkicking。””Youwillstartto-morrow。””Wishitwereto-day。””Andyouwillfirstinquire，notfor0。B。，that’stooindefinite；
　　butforayounggirlbythenameofDorisScott。Sheholdstheclew；orrathersheistheclewtothissecond0。B。””Anotherwoman！””No，achild；-well，Iwon’tsaychildexactly；shemustbesixteen。””DorisScott。””ShelivesinDerby。Derbyisasmallplace。Youwillhavenotroubleinfindingthischild。ItwastoherMissChalloner’slastletterwasaddressed。Theone-””Ibegintosee。””No，youdon’t，Sweetwater。Theaffairisasblindasyourhat；
　　nobodysees。We’rejustfeelingalongathread。O。B。’sletters-therealO。B。，Imean，arethemanliesteffusionspossible。
　　He’snomoreofamilksopthanthisBrotherson；andunlikeyourindomitablefriendheseemstohavesomeheart。Ionlywishhe’dgivenussomefacts；theywouldhavebeenserviceable。ButthelettersrevealnothingexceptthatheknewDoris。Hewritesinoneofthem：’Dorisislearningtoembroider。It’slikeafairyweavingacobweb！’Dorisisn’taverycommonname。ShemustbethesamelittlegirltowhomMissChallonerwrotefromtimetotime。””WasthislettersignedO。B。?””Yes；theyallare。TheonlydifferencebetweenhislettersandBrotherson’sisthis：Brotherson’sretainthedateandaddress；
　　thesecondO。B。’sdonot。””Hownot?Tornoff，doyoumean?””Yes，orrather，neatlycutaway；andasnoneoftheenvelopeswerekept，theonlymeansbywhichwecanlocatethewriteristhroughthisgirlDoris。””IfIrememberrightlyMissChalloner’slettertothischildwasfreefromallmystery。””Quiteso。Itisasopenastheday。ThatiswhyithasbeenmentionedasshowingthefreedomofMissChalloner’smindfiveminutesbeforethatfatalthrust。”
　　SweetwatertookupthesheetMr。Grycepushedtowardshimandre-readtheselines：”DearLittleDoris：”Itisasnowynight，butitisallbrightinsideandIfeelnochillinmindorbody。IhopeitissointhelittlecottageinDerby；thatmylittlefriendisashappywithharshwindsblowingfromthemountainsasshewasonthesummerdayshecametoseemeatthishotel。Iliketothinkofherascheerfulandbeaming，rejoicingintaskswhichmakehersowomanlyandsweet。Sheisoften，ofteninmymind。”Affectionatelyyourfriend，”EDITHA。CHALLONER。””Thattoachildofsixteen！””Justso。””D-o-r-i-sspellssomethingbesidesDoris。””YetthereisaDoris。RememberthatO。B。saysinoneofhisletters，’Dorisislearningtoembroider。’”Yes，Irememberthat。””SoyoumustfirstfindDoris。””Verygood，sir。””AndasMissChalloner’sletterwasdirectedtoDerby，Pennsylvania，youwillgotoDerby。””Yes，sir。””Anythingmore?””I’vebeenreadingthisletteragain。””It’sworthit。””Thelastsentenceexpressesahope。””Thathasbeennoted。”
　　Sweetwater’seyesslowlyrosetilltheyrestedonMr。Gryce’sface：”I’llclingtothethreadyou’vegivenme。I’llworkmyselfthroughthelabyrinthbeforeustillIreachHIM。”
　　Mr。Grycesmiled；buttherewasmoreage，wisdomandsympathyforyouthfulenthusiasminthatsmilethantherewasconfidenceorhope。
　　BOOKIII
　　THEHEARTOFMAN