My　observations　of　No。　427　Park　Lane　did　little　to　clear　up　the
  problem　in　which　I　was　interested。　The　house　was　separated　from　the
  street　by　a　low　wall　and　railing；　the　whole　not　more　than　five　feet
  high。　It　was　perfectly　easy；　therefore；　for　anyone　to　get　into　the
  garden；　but　the　window　was　entirely　inaccessible；　since　there　was　no
  waterpipe　or　anything　which　could　help　the　most　active　man　to　climb
  it。　More　puzzled　than　ever；　I　retraced　my　steps　to　Kensington。　I　had
  not　been　in　my　study　five　minutes　when　the　maid　entered　to　say　that
  a　person　desired　to　see　me。　To　my　astonishment　it　was　none　other
  than　my　strange　old　book　collector；　his　sharp；　wizened　face　peering
  out　from　a　frame　of　white　hair；　and　his　precious　volumes；　a　dozen　of
  them　at　least；　wedged　under　his　right　arm。
  〃You're　surprised　to　see　me；　sir；〃　said　he；　in　a　strange；　croaking
  voice。
  I　acknowledged　that　I　was。
  〃Well；　I've　a　conscience；　sir；　and　when　I　chanced　to　see　you　go　into
  this　house；　as　I　came　hobbling　after　you；　I　thought　to　myself；　I'll
  just　step　in　and　see　that　kind　gentleman；　and　tell　him　that　if　I　was　a
  bit　gruff　in　my　manner　there　was　not　any　harm　meant；　and　that　I　am
  much　obliged　to　him　for　picking　up　my　books。〃
  〃You　make　too　much　of　a　trifle；〃　said　I。　〃May　I　ask　how　you　knew　who
  I　was？〃
  〃Well；　sir；　if　it　isn't　too　great　a　liberty；　I　am　a　neighbour　of
  yours；　for　you'll　find　my　little　bookshop　at　the　corner　of　Church
  Street；　and　very　happy　to　see　you；　I　am　sure。　Maybe　you　collect
  yourself；　sir。　Here's　British　Birds；　and　Catullus；　and　The　Holy　War…　a
  bargain；　every　one　of　them。　With　five　volumes　you　could　just　fill　that
  gap　on　that　second　shelf。　It　looks　untidy；　does　it　not；　sir？〃
  I　moved　my　head　to　look　at　the　cabinet　behind　me。　When　I　turned
  again；　Sherlock　Holmes　was　standing　smiling　at　me　across　my　study
  table。　I　rose　to　my　feet；　stared　at　him　for　some　seconds　in　utter
  amazement；　and　then　it　appears　that　I　must　have　fainted　for　the
  first　and　the　last　time　in　my　life。　Certainly　a　gray　mist　swirled
  before　my　eyes；　and　when　it　cleared　I　found　my　collar…ends　undone
  and　the　tingling　after…taste　of　brandy　upon　my　lips。　Holmes　was
  bending　over　my　chair；　his　flask　in　his　hand。
  〃My　dear　Watson；〃　said　the　well…remembered　voice；　〃I　owe　you　a
  thousand　apologies。　I　had　no　idea　that　you　would　be　so　affected。〃
  I　gripped　him　by　the　arms。
  〃Holmes！〃　I　cried。　〃Is　it　really　you？　Can　it　indeed　be　that　you
  are　alive？　Is　it　possible　that　you　succeeded　in　climbing　out　of　that
  awful　abyss？〃
  〃Wait　a　moment；〃　said　he。　〃Are　you　sure　that　you　are　really　fit　to
  discuss　things？　I　have　given　you　a　serious　shock　by　my　unnecessarily
  dramatic　reappearance。〃
  〃I　am　all　right；　but　indeed；　Holmes；　I　can　hardly　believe　my　eyes。
  Good　heavens！　to　think　that　you…　you　of　all　men…　should　be　standing　in
  my　study。〃　Again　I　gripped　him　by　the　sleeve；　and　felt　the　thin；
  sinewy　arm　beneath　it。　〃Well；　you're　not　a　spirit　anyhow；〃　said　I。　〃My
  dear　chap；　I'm　overjoyed　to　see　you。　Sit　down；　and　tell　me　how　you
  came　alive　out　of　that　dreadful　chasm。〃
  He　sat　opposite　to　me；　and　lit　a　cigarette　in　his　old；　nonchalant
  manner。　He　was　dressed　in　the　seedy　frockcoat　of　the　book　merchant；
  but　the　rest　of　that　individual　lay　in　a　pile　of　white　hair　and　old
  books　upon　the　table。　Holmes　looked　even　thinner　and　keener　than　of
  old；　but　there　was　a　dead…white　tinge　in　his　aquiline　face　which
  told　me　that　his　life　recently　had　not　been　a　healthy　one。
  〃I　am　glad　to　stretch　myself；　Watson；〃　said　he。　〃It　is　no　joke
  when　a　tall　man　has　to　take　a　foot　off　his　stature　for　several　hours
  on　end。　Now；　my　dear　fellow；　in　the　matter　of　these　explanations；　we
  have；　if　I　may　ask　for　your　cooperation；　a　hard　and　dangerous
  night's　work　in　front　of　us。　Perhaps　it　would　be　better　if　I　gave
  you　an　account　of　the　whole　situation　when　that　work　is　finished。〃
  〃I　am　full　of　curiosity。　I　should　much　prefer　to　hear　now。〃
  〃You'll　come　with　me　to…night？〃
  〃When　you　like　and　where　you　like。〃
  〃This　is；　indeed；　like　the　old　days。　We　shall　have　time　for　a
  mouthful　of　dinner　before　we　need　go。　Well；　then；　about　that　chasm。
  I　had　no　serious　difficulty　in　getting　out　of　it；　for　the　very
  simple　reason　that　I　never　was　in　it。〃
  〃You　never　were　in　it？〃
  〃No；　Watson；　I　never　was　in　it。　My　note　to　you　was　absolutely
  genuine。　I　had　little　doubt　that　I　had　come　to　the　end　of　my　career
  when　I　perceived　the　somewhat　sinister　figure　of　the　late　Professor
  Moriarty　standing　upon　the　narrow　pathway　which　led　to　safety。　I
  read　an　inexorable　purpose　in　his　gray　eyes。　I　exchanged　some
  remarks　with　him；　therefore；　and　obtained　his　courteous　permission
  to　write　the　short　note　which　you　afterwards　received。　I　left　it
  with　my　cigarette…box　and　my　stick；　and　I　walked　along　the　pathway；
  Moriarty　still　at　my　heels。　When　I　reached　the　end　I　stood　at　bay。
  He　drew　no　weapon；　but　he　rushed　at　me　and　threw　his　long　arms
  around　me。　He　knew　that　his　own　game　was　up；　and　was　only　anxious　to
  revenge　himself　upon　me。　We　tottered　together　upon　the　brink　of　the
  fall。　I　have　some　knowledge；　however；　of　baritsu；　or　the　Japanese
  system　of　wrestling；　which　has　more　than　once　been　very　useful　to
  me。　I　slipped　through　his　grip；　and　he　with　a　horrible　scream　kicked
  madly　for　a　few　seconds；　and　clawed　the　air　with　both　his　hands。　But
  for　all　his　efforts　he　could　not　get　his　balance；　and　over　he　went。
  With　my　face　over　the　brink；　I　saw　him　fall　for　a　long　way。　Then　he
  struck　a　rock；　bounded　off；　and　splashed　into　the　water。〃
  I　listened　with　amazement　to　this　explanation；　which　Holmes
  delivered　between　the　puffs　of　his　cigarette。
  〃But　the　tracks！〃　I　cried。　〃I　saw；　with　my　own　eyes；　that　two　went
  down　the　path　and　none　returned。〃
  〃It　came　about　in　this　way。　The　instant　that　the　Professor　had
  disappeared；　it　struck　me　what　a　really　extraordinarily　lucky　chance
  Fate　had　placed　in　my　way。　I　knew　that　Moriarty　was　not　the　only　man
  who　had　sworn　my　death。　There　were　at　least　three　others　whose
  desire　for　vengeance　upon　me　would　only　be　increased　by　the　death　of
  their　leader。　They　were　all　most　dangerous　men。　One　or　other　would
  certainly　get　me。　On　the　other　hand；　if　all　the　world　was　convinced
  that　I　was　dead　they　would　take　liberties；　these　men；　they　would
  soon　lay　themselves　open；　and　sooner　or　later　I　could　destroy　them。
  Then　it　would　be　time　for　me　to　announce　that　I　was　still　in　the
  land　of　the　living。　So　rapidly　does　the　brain　act　that　I　believe　I　had
  thought　this　all　out　before　Professor　Moriarty　had　reached　the
  bottom　of　the　Reichenbach　Fall。
  〃I　stood　up　and　examined　the　rocky　wall　behind　me。　In　your
  picturesque　account　of　the　matter；　which　I　read　with　great　interest
  some　months　later；　you　assert　that　the　wall　was　sheer。　That　was　not
  literally　true。　A　few　small　footholds　presented　themselves；　and
  there　was　some　indication　of　a　ledge。　The　cliff　is　so　high　that　to
  climb　it　all　was　an　obvious　impossibility；　and　it　was　equally
  impossible　to　make　my　way　along　the　wet　path　without　leaving　some
  tracks。　I　might；　it　is　true；　have　reversed　my　boots；　as　I　have　done　on
  similar　occasions；　but　the　sight　of　three　sets　of　tracks　in　one
  direction　would　certainly　have　suggested　a　deception。　On　the　whole；
  then；　it　was　best　that　I　should　risk　the　climb。　It　was　not　a
  pleasant　business；　Watson。　The　fall　roared　beneath　me。　I　am　not　a
  fanciful　person；　but　I　give　you　my　word　that　I　seemed　to　hear
  Moriarty's　voice　screaming　at　me　out　of　the　abyss。　A　mistake　would
  have　been　fatal。　More　than　once；　as　tufts　of　grass　came　out　in　my　hand
  or　my　foot　slipped　in　the　wet　notches　of　the　rock；　I　thought　that　I
  was　gone。　But　I　struggled　upward；　and　at　last　I　reached　a　ledge
  several　feet　deep　and　covered　with　soft　green　moss；　where　I　could
  lie　unseen；　in　the　most　perfect　comfort。　There　I　was　stretched；　when
  you；　my　dear　Watson；　and　all　your　following　were　investigating　in
  the　most　sympathetic　and　inefficient　manner　the　circumstances　of　my
  death。
  〃At　last；　when　you　had　all　formed　your　inevitable　and　totally
  erroneous　conclusions；　you　departed　for　the　hotel；　and　I　was　left
  alone。　I　had　imagined　that　I　had　reached　the　end　of　my　adventures；　but
  a　very　unexpected　occurrence　showed　me　that　there　were　surprises　still
  in　store　for　me。　A　huge　rock；　falling　from　above；　boomed　past　me；
  struck　the　path；　and　bounded　over　into　the　chasm。　For　an　instant　I
  thought　that　it　was　an　accident；　but　a　moment　later；　looking　up；　I　saw
  a　man's　head　against　the　darkening　sky；　and　another　stone　struck　the
  very　ledge　upon　which　I　was　stretched；　within　a　foot　of　my　head。　Of
  course；　the　meaning　of　this　was　obvious。　Moriarty　had　not　been
  alone。　A　confederate…　and　even　that　one　glance　had　told　me　how
  dangerous　a　man　that　confederate　was…　had　kept　guard　while　the
  Professor　had　attacked　me。　From　a　distance；　unseen　by　me；　he　had
  been　a　witness　of　his　friend's　death　and　of　my　escape。　He　had
  waited；　and　then　making　his　way　round　to　the　top　of　the　cliff；　he
  had　endeavoured　to　succeed　where　his　comrade　had　failed。
  〃I　did　not　take　long　to　think　abo