agent。　They　could　not　agree　as　to　price。　He　started　home　again；　but
  the　agent　went　with　him。　In　the　train　the　agent　murdered　him；　took　the
  more　essential　papers；　and　threw　his　body　from；　the　carriage。　That
  would　account　for　everything；　would　it　not？〃
  〃Why　had　he　no　ticket？〃
  〃The　ticket　would　have　shown　which　station　was　nearest　the　agent's
  house。　Therefore　he　took　it　from　the　murdered　man's　pocket。〃
  〃Good；　Lestrade；　very　good；〃　said　Holmes。　〃Your　theory　holds
  together。　But　if　this　is　true；　then　the　case　is　at　an　end。　On　the
  one　hand；　the　traitor　is　dead。　On　the　other；　the　plans　of　the
  Bruce…Partington　submarine　are　presumably　already　on　the　Continent。
  What　is　there　for　us　to　do？〃
  〃To　act；　Sherlock…　to　act！〃　cried　Mycroft；　springing　to　his　feet。
  〃All　my　instincts　are　against　this　explanation。　Use　your　powers！　Go　to
  the　scene　of　the　crime！　See　the　people　concerned！　Leave　no　stone
  unturned！　In　all　your　career　you　have　never　had　so　great　a　chance　of
  serving　your　country。〃
  〃Well；　well！〃　said　Holmes；　shrugging　his　shoulders。　〃Come；　Watson！
  And　you；　Lestrade；　could　you　favour　us　with　your　company　for　an　hour
  or　two？　We　will　begin　our　investigation　by　a　visit　to　Aldgate　Station。
  Good…bye；　Mycroft。　I　shall　let　you　have　a　report　before　evening；　but　I
  warn　you　in　advance　that　you　have　little　to　expect。〃
  An　hour　later　Holmes；　Lestrade　and　I　stood　upon　the　Underground
  railroad　at　the　point　where　it　emerges　from　the　tunnel　immediately
  before　Aldgate　Station。　A　courteous　red…faced　old　gentleman
  represented　the　railway　company。
  〃This　is　where　the　young　man's　body　lay；〃　said　he；　indicating　a　spot
  about　three　feet　from　the　metals。　〃It　could　not　have　fallen　from
  above；　for　these；　as　you　see；　are　all　blank　walls。　Therefore；　it　could
  only　have　come　from　a　train；　and　that　train；　so　far　as　we　can　trace
  it；　must　have　passed　about　midnight　on　Monday。〃
  〃Have　the　carriages　been　examined　for　any　sign　of　violence？〃
  〃There　are　no　such　signs；　and　no　ticket　has　been　found。〃
  〃No　record　of　a　door　being　found　open？〃
  〃None。〃
  〃We　have　had　some　fresh　evidence　this　morning；〃　said　Lestrade。　〃A
  passenger　who　passed　Aldgate　in　an　ordinary　Metropolitan　train　about
  11：40　on　Monday　night　declares　that　he　heard　a　heavy　thud；　as　of　a
  body　striking　the　line；　just　before　the　train　reached　the　station。
  There　was　dense　fog；　however；　and　nothing　could　be　seen。　He　made　no
  report　of　it　at　the　time。　Why；　whatever　is　the　matter　with　Mr。
  Holmes？〃
  My　friend　was　standing　with　an　expression　of　strained　intensity　upon
  his　face；　staring　at　the　railway　metals　where　they　curved　out　of　the
  tunnel。　Aldgate　is　a　junction；　and　there　was　a　network　of　points。　On
  these　his　eager；　questioning　eyes　were　fixed；　and　I　saw　on　his　keen；
  alert　face　that　tightening　of　the　lips；　that　quiver　of　the　nostrils；
  and　concentration　of　the　heavy；　tufted　brows　which　I　knew　so　well。
  〃Points；〃　he　muttered；　〃the　points。〃
  〃What　of　it？　What　do　you　mean？〃
  〃I　suppose　there　are　no　great　number　of　points　on　a　system　such　as
  this？〃
  〃No；　there　are　very　few。〃
  〃And　a　curve；　too。　Points；　and　a　curve。　By　Jove！　if　it　were　only
  so。〃
  〃What　is　it；　Mr。　Holmes？　Have　you　a　clue？〃
  〃An　idea…　an　indication；　no　more。　But　the　case　certainly　grows　in
  interest。　Unique；　perfectly　unique；　and　yet　why　not？　I　do　not　see
  any　indications　of　bleeding　on　the　line。〃
  〃There　were　hardly　any。〃
  〃But　I　understand　that　there　was　a　considerable　wound。〃
  〃The　bone　was　crushed；　but　there　was　no　great　external　injury。〃
  〃And　yet　one　would　have　expected　some　bleeding。　Would　it　be　possible
  for　me　to　inspect　the　train　which　contained　the　passenger　who　heard
  the　thud　of　a　fall　in　the　fog？〃
  〃I　fear　not；　Mr。　Holmes。　The　train　has　been　broken　up　before　now；
  and　the　carriages　redistributed。〃
  〃I　can　assure　you；　Mr。　Holmes；〃　said　Lestrade；　〃that　every
  carriage　has　been　carefully　examined。　I　saw　to　it　myself。〃
  It　was　one　of　my　friend's　most　obvious　weaknesses　that　he　was
  impatient　with　less　alert　intelligences　than　his　own。
  〃Very　likely；〃　said　he；　turning　away。　〃As　it　happens；　it　was　not　the
  carriages　which　I　desired　to　examine。　Watson；　we　have　done　all　we
  can　here。　We　need　not　trouble　you　any　further；　Mr。　Lestrade。　I　think
  our　investigations　must　now　carry　us　to　Woolwich。〃
  At　London　Bridge；　Holmes　wrote　a　telegram　to　his　brother；　which　he
  handed　to　me　before　dispatching　it。　It　ran　thus：
  See　some　light　in　the　darkness；　but　it　may　possibly　flicker　out。
  Meanwhile；　please　send　by　messenger；　to　await　return　at　Baker
  Street；　a　complete　list　of　all　foreign　spies　or　international　agents
  known　to　be　in　England；　with　full　address。
  SHERLOCK。
  〃That　should　be　helpful；　Watson；〃　he　remarked　as　we　took　our　seats
  in　the　Woolwich　train。　〃We　certainly　owe　Brother　Mycroft　a　debt　for
  having　introduced　us　to　what　promises　to　be　a　really　very　remarkable
  case。〃
  His　eager　face　still　wore　that　expression　of　intense　and　high…strung
  energy；　which　showed　me　that　some　novel　and　suggestive　circumstance
  had　opened　up　a　stimulating　line　of　thought。　See　the　foxhound　with
  hanging　cars　and　drooping　tail　as　it　lolls　about　the　kennels；　and
  compare　it　with　the　same　hound　as；　with　gleaming　eyes　and　straining
  muscles；　it　runs　upon　a　breast…high　scent…　such　was　the　change　in
  Holmes　since　the　morning。　He　was　a　different　man　from　the　limp　and
  lounging　figure　in　the　mouse…coloured　dressing…gown　who　had　prowled　so
  restlessly　only　a　few　hours　before　round　the　fog…girt　room。
  〃There　is　material　here。　There　is　scope；〃　said　he。　〃I　am　dull　indeed
  not　to　have　understood　its　possibilities。〃
  〃Even　now　they　are　dark　to　me。〃
  〃The　end　is　dark　to　me　also；　but　I　have　hold　of　one　idea　which　may
  lead　us　far。　The　man　met　his　death　elsewhere；　and　his　body　was　on
  the　roof　of　a　carriage。〃
  〃On　the　roof！〃
  〃Remarkable；　is　it　not？　But　consider　the　facts。　Is　it　a
  coincidence　that　it　is　found　at　the　very　point　where　the　train　pitches
  and　sways　as　it　comes　round　on　the　points？　Is　not　that　the　place　where
  an　object　upon　the　roof　might　be　expected　to　fall　off？　The　points
  would　affect　no　object　inside　the　train。　Either　the　body　fell　from　the
  roof；　or　a　very　curious　coincidence　has　occurred。　But　now　consider　the
  question　of　the　blood。　Of　course；　there　was　no　bleeding　on　the　line　if
  the　body　had　bled　elsewhere。　Each　fact　is　suggestive　in　itself。
  Together　they　have　a　cumulative　force。〃
  〃And　the　ticket；　too！〃　I　cried。
  〃Exactly。　We　could　not　explain　the　absence　of　a　ticket。　This　would
  explain　it。　Everything　fits　together。〃
  〃But　suppose　it　were　so；　we　are　still　as　far　as　ever　from
  unravelling　the　mystery　of　his　death。　Indeed；　it　becomes　not　simpler
  but　stranger。〃
  〃Perhaps；〃　said　Holmes　thoughtfully；　〃perhaps。〃　He　relapsed　into　a
  silent　reverie；　which　lasted　until　the　slow　train　drew　up　at　last　in
  Woolwich　Station。　There　he　called　a　cab　and　drew　Mycroft's　paper
  from　his　pocket。
  〃We　have　quite　a　little　round　of　afternoon　calls　to　make；〃　said
  he。　〃I　think　that　Sir　James　Walter　claims　our　first　attention。〃
  The　house　of　the　famous　official　was　a　fine　villa　with　green　lawns
  stretching　down　to　the　Thames。　As　we　reached　it　the　fog　was　lifting；
  and　a　thin；　watery　sunshine　was　breaking　through。　A　butler　answered
  our　ring。
  〃Sir　James；　sir！〃　said　he　with　solemn　face。　〃Sir　James　died　this
  morning。〃
  〃Good　heavens！〃　cried　Holmes　in　amazement。　〃How　did　he　die？〃
  〃Perhaps　you　would　care　to　step　in；　sir；　and　see　his　brother；
  Colonel　Valentine？〃
  〃Yes；　we　had　best　do　so。〃
  We　were　ushered　into　a　dim…lit　drawing…room；　where　an　instant
  later　we　were　joined　by　a　very　tall；　handsome；　light…bearded　man　of
  fifty；　the　younger　brother　of　the　dead　scientist。　His　wild　eyes；
  stained　cheeks；　and　unkempt　hair　all　spoke　of　the　sudden　blow　which
  had　fallen　upon　the　household。　He　was　hardly　articulate　as　he　spoke　of
  it。
  〃It　was　this　horrible　scandal；〃　said　he。　〃My　brother；　Sir　James；　was
  a　man　of　very　sensitive　honour；　and　he　could　not　survive　such　an
  affair。　It　broke　his　heart。　He　was　always　so　proud　of　the　efficiency
  of　his　department；　and　this　was　a　crushing　blow。〃
  〃We　had　hoped　that　he　might　have　given　us　some　indications　which
  would　have　helped　us　to　clear　the　matter　up。〃
  〃I　assure　you　that　it　was　all　a　mystery　to　him　as　it　is　to　you　and
  to　all　of　us。　He　had　already　put　all　his　knowledge　at　the　disposal
  of　the　police。　Naturally　he　had　no　doubt　that　Cadogan　West　was　guilty。
  But　all　the　rest　was　inconceivable。〃
  〃You　cannot　throw　any　new　light　upon　the　affair？〃
  〃I　know　nothing　myself　save　what　I　have　read　or　heard。　I　have　no
  desire　to　be　discourteous；　but　you　can　understand；　Mr。　Holmes；　that　we
  are　much　disturbed　at　present；　and　I　must　ask　you　to　hasten　this
  interview　to　an　end。〃
  〃This　is　indeed　an　unexpected　development；〃　said　my　friend　when　we
  had　regained　the　cab。　〃I　wonder　if　the　death　was　natural；　or　whether
  the　poor　old　fellow　killed　himself！　If　the　latter；　may　it　be　taken
  as　some　sign　of　self…reproach　for　duty　neglected？　We　must　l