g　his　black　eyebrows。　　〃I　live；　myself；　in　Himylaya　Mansions；　round　the　corner。　　Perhaps　you　might　care　to　come　with　me；　I　can　go　to　my　rooms　and　sort　out　these　queer　Welkin　documents；　while　you　run　round　and　get　your　friend　the　detective。〃　　　　　〃You　are　very　good；〃　said　Angus　politely。　　〃Well；　the　sooner　we　act　the　better。〃　　　　　Both　men；　with　a　queer　kind　of　impromptu　fairness；　took　the　same　sort　of　formal　farewell　of　the　lady；　and　both　jumped　into　the　brisk　little　car。　　As　Smythe　took　the　handles　and　they　turned　the　great　corner　of　the　street；　Angus　was　amused　to　see　a　gigantesque　poster　of　〃Smythe's　Silent　Service；〃　with　a　picture　of　a　huge　headless　iron　doll；　carrying　a　saucepan　with　the　legend；　〃A　Cook　Who　is　Never　Cross。〃　　　　　〃I　use　them　in　my　own　flat；〃　said　the　little　black…bearded　man；　laughing；　〃partly　for　advertisements；　and　partly　for　real　convenience。　　Honestly；　and　all　above　board；　those　big　clockwork　dolls　of　mine　do　bring　your　coals　or　claret　or　a　timetable　quicker　than　any　live　servants　I've　ever　known；　if　you　know　which　knob　to　press。　　But　I'll　never　deny；　between　ourselves；　that　such　servants　have　their　disadvantages；　too。　　　　　〃Indeed？〃　said　Angus；　〃is　there　something　they　can't　do？〃　　　　　〃Yes；〃　replied　Smythe　coolly；　〃they　can't　tell　me　who　left　those　threatening　letters　at　my　flat。〃　　　　　The　man's　motor　was　small　and　swift　like　himself；　in　fact；　like　his　domestic　service；　it　was　of　his　own　invention。　　If　he　was　an　advertising　quack；　he　was　one　who　believed　in　his　own　wares。　The　sense　of　something　tiny　and　flying　was　accentuated　as　they　swept　up　long　white　curves　of　road　in　the　dead　but　open　daylight　of　evening。　　Soon　the　white　curves　came　sharper　and　dizzier；　they　were　upon　ascending　spirals；　as　they　say　in　the　modern　religions。　For；　indeed；　they　were　cresting　a　corner　of　London　which　is　almost　as　precipitous　as　Edinburgh；　if　not　quite　so　picturesque。　　Terrace　rose　above　terrace；　and　the　special　tower　of　flats　they　sought；　rose　above　them　all　to　almost　Egyptian　height；　gilt　by　the　level　sunset。　　The　change；　as　they　turned　the　corner　and　entered　the　crescent　known　as　Himylaya　Mansions；　was　as　abrupt　as　the　opening　of　a　window；　for　they　found　that　pile　of　flats　sitting　above　London　as　above　a　green　sea　of　slate。　　Opposite　to　the　mansions；　on　the　other　side　of　the　gravel　crescent；　was　a　bushy　enclosure　more　like　a　steep　hedge　or　dyke　than　a　garden；　and　some　way　below　that　ran　a　strip　of　artificial　water；　a　sort　of　canal；　like　the　moat　of　that　embowered　fortress。　　As　the　car　swept　round　the　crescent　it　passed；　at　one　corner；　the　stray　stall　of　a　man　selling　chestnuts；　and　right　away　at　the　other　end　of　the　curve；　Angus　could　see　a　dim　blue　policeman　walking　slowly。　　These　were　the　only　human　shapes　in　that　high　suburban　solitude；　but　he　had　an　irrational　sense　that　they　expressed　the　speechless　poetry　of　London。　　He　felt　as　if　they　were　figures　in　a　story。　　　　　The　little　car　shot　up　to　the　right　house　like　a　bullet；　and　shot　out　its　owner　like　a　bomb　shell。　　He　was　immediately　inquiring　of　a　tall　commissionaire　in　shining　braid；　and　a　short　porter　in　shirt　sleeves；　whether　anybody　or　anything　had　been　seeking　his　apartments。　　He　was　assured　that　nobody　and　nothing　had　passed　these　officials　since　his　last　inquiries；　whereupon　he　and　the　slightly　bewildered　Angus　were　shot　up　in　the　lift　like　a　rocket；　till　they　reached　the　top　floor。　　　　　〃Just　come　in　for　a　minute；〃　said　the　breathless　Smythe。　　〃I　want　to　show　you　those　Welkin　letters。　　Then　you　might　run　round　the　corner　and　fetch　your　friend。〃　　He　pressed　a　button　concealed　in　the　wall；　and　the　door　opened　of　itself。　　　　　It　opened　on　a　long；　commodious　ante…room；　of　which　the　only　arresting　features；　ordinarily　speaking；　were　the　rows　of　tall　half…human　mechanical　figures　that　stood　up　on　both　sides　like　tailors'　dummies。　　Like　tailors'　dummies　they　were　headless；　and　like　tailors'　dummies　they　had　a　handsome　unnecessary　humpiness　in　the　shoulders；　and　a　pigeon…breasted　protuberance　of　chest；　but　barring　this；　they　were　not　much　more　like　a　human　figure　than　any　automatic　machine　at　a　station　that　is　about　the　human　height。　They　had　two　great　hooks　like　arms；　for　carrying　trays；　and　they　were　painted　pea…green；　or　vermilion；　or　black　for　convenience　of　distinction；　in　every　other　way　they　were　only　automatic　machines　and　nobody　would　have　looked　twice　at　them。　　On　this　occasion；　at　least；　nobody　did。　　For　between　the　two　rows　of　these　domestic　dummies　lay　something　more　interesting　than　most　of　the　mechanics　of　the　world。　　It　was　a　white；　tattered　scrap　of　paper　scrawled　with　red　ink；　and　the　agile　inventor　had　snatched　it　up　almost　as　soon　as　the　door　flew　open。　　He　handed　it　to　Angus　without　a　word。　The　red　ink　on　it　actually　was　not　dry；　and　the　message　ran；　〃If　you　have　been　to　see　her　today；　I　shall　kill　you。〃　　　　　There　was　a　short　silence；　and　then　Isidore　Smythe　said　quietly；　〃Would　you　like　a　little　whiskey？　　I　rather　feel　as　if　I　should。〃　　　　　〃Thank　you；　I　should　like　a　little　Flambeau；〃　said　Angus；　gloomily。　　〃This　business　seems　to　me　to　be　getting　rather　grave。　I'm　going　round　at　once　to　fetch　him。〃　　　　　〃Right　you　are；〃　said　the　other；　with　admirable　cheerfulness。　〃Bring　him　round　here　as　quick　as　you　can。〃　　　　　But　as　Angus　closed　the　front　door　behind　him　he　saw　Smythe　push　back　a　button；　and　one　of　the　clockwork　images　glided　from　its　place　and　slid　along　a　groove　in　the　floor　carrying　a　tray　with　syphon　and　decanter。　　There　did　seem　something　a　trifle　weird　about　leaving　the　little　man　alone　among　those　dead　servants；　who　were　coming　to　life　as　the　door　closed。　　　　　Six　steps　down　from　Smythe's　landing　the　man　in　shirt　sleeves　was　doing　something　with　a　pail。　　Angus　stopped　to　extract　a　promise；　fortified　with　a　prospective　bribe；　that　he　would　remain　in　that　place　until　the　return　with　the　detective；　and　would　keep　count　of　any　kind　of　stranger　coming　up　those　stairs。　　Dashing　down　to　the　front　hall　he　then　laid　similar　charges　of　vigilance　on　the　commissionaire　at　the　front　door；　from　whom　he　learned　the　simplifying　circumstances　that　there　was　no　back　door。　　Not　content　with　this；　he　captured　the　floating　policeman　and　induced　him　to　stand　opposite　the　entrance　and　watch　it；　and　finally　paused　an　instant　for　a　pennyworth　of　chestnuts；　and　an　inquiry　as　to　the　probable　length　of　the　merchant's　stay　in　the　neighbourhood。　　　　　The　chestnut　seller；　turning　up　the　collar　of　his　coat；　told　him　he　should　probably　be　moving　shortly；　as　he　thought　it　was　going　to　snow。　　Indeed；　the　evening　was　growing　grey　and　bitter；　but　Angus；　with　all　his　eloquence；　proceeded　to　nail　the　chestnut　man　to　his　post。　　　　　〃Keep　yourself　warm　on　your　own　chestnuts；〃　he　said　earnestly。　〃Eat　up　your　whole　stock；　I'll　make　it　worth　your　while。　　I'll　give　you　a　sovereign　if　you'll　wait　here　till　I　come　back；　and　then　tell　me　whether　any　man；　woman；　or　child　has　gone　into　that　house　where　the　commissionaire　is　standing。〃　　　　　He　then　walked　away　smartly；　with　a　last　look　at　the　besieged　tower。　　　　　〃I've　made　a　ring　round　that　room；　anyhow；〃　he　said。　　〃They　can't　all　four　of　them　be　Mr。　Welkin's　accomplices。〃　　　　　Lucknow　Mansions　were；　so　to　speak；　on　a　lower　platform　of　that　hill　of　houses；　of　which　Himylaya　Mansions　might　be　called　the　peak。　　Mr。　Flambeau's　semi…official　flat　was　on　the　ground　floor；　and　presented　in　every　way　a　marked　contrast　to　the　American　machinery　and　cold　hotel…like　luxury　of　the　flat　of　the　Silent　Service。　　Flambeau；　who　was　a　friend　of　Angus；　received　him　in　a　rococo　artistic　den　behind　his　office；　of　which　the　ornaments　were　sabres；　harquebuses；　Eastern　curiosities；　flasks　of　Italian　wine；　savage　cooking…pots；　a　plumy　Persian　cat；　and　a　small　dusty…looking　Roman　Catholic　priest；　who　looked　particularly　out　of　place。　　　　　〃This　is　my　friend　Father　Brown；〃　said　Flambeau。　　〃I've　often　wanted　you　to　meet　him。　　Splendid　weather；　this；　a　little　cold　for　Southerners　like　me。〃　　　　　〃Yes；　I　think　it　will　keep　clear；〃　said　Angus；　sitting　down　on　a　violet…striped　Eastern　ottoman。　　　　　〃No；〃　said　the　priest　quietly；　〃it　has　begun　to　snow。〃　　　　　And；　indeed；　as　he　spoke；　the　first　few　flakes；　foreseen　by　the　man　of　chestnuts；　began　to　drift　across　the　darkening　windowpane。　　　　　〃Well；〃　said　Angus　heavily。　　〃I'm　afraid　I've　come　on　business；　and　rather　jumpy　business　at　that。　　The　fact　is；　Flambeau；　within　a　stone's　throw　of　your　house　is　a　fellow　who　badly　wants　your　help；　he's　perpetually　being　haunted　and　threatened　by　an　invisible　enemy　a　scoundrel　whom　nobody　has　even　seen。〃　　As　Angus　proceeded　to　tell　the　whole　tale　of　Smythe　and　Welkin；　beginning　with　Laura's　story；　and　going　on　with　his　own；　the　supernatural　laugh　at　the　corner　of　two　empty　streets；　the　strange　distinct　words　spoken　in　an　empty　room；　Flambeau　grew　more　and　more　vividly　concerned；　and　the　little　priest　seemed　to　be　left　out　of　it；　like　a　piece　of　furniture。　　When　it　came　to　the　scribbled　stamp…paper　pasted　on　the　window；　Flambeau　rose；　seeming　to　fill　the　room　with　his　huge　shoulders。　　　　　〃If　you　don't　mind；〃　he　said；　〃I　think　you　had　better　tell　me　the　rest　on　the　nearest　road　to　this　man's　house。　　It　strikes　me；　somehow；　that　there　is　no　time　to　be　lost。〃　　　　　〃Delighted；〃　said　Angus；　rising　also；　〃though　he