vy　lidsa　face　of　a　wicked　Roman　emperor；　with；　perhaps；　a　distant　touch　of　a　Chinese　emperor。　　All　present　seemed　to　look　at　it　with　the　coldest　eye　of　ignorance。　　Nothing　else　could　be　noted　about　the　man　except　that；　as　they　had　lifted　his　body；　they　had　seen　underneath　it　the　white　gleam　of　a　shirt…front　defaced　with　a　red　gleam　of　blood。　　As　Dr。　Simon　said；　the　man　had　never　been　of　their　party。　　But　he　might　very　well　have　been　trying　to　join　it；　for　he　had　come　dressed　for　such　an　occasion。　　　　　Valentin　went　down　on　his　hands　and　knees　and　examined　with　his　closest　professional　attention　the　grass　and　ground　for　some　twenty　yards　round　the　body；　in　which　he　was　assisted　less　skillfully　by　the　doctor；　and　quite　vaguely　by　the　English　lord。　Nothing　rewarded　their　grovellings　except　a　few　twigs；　snapped　or　chopped　into　very　small　lengths；　which　Valentin　lifted　for　an　instant's　examination　and　then　tossed　away。　　　　　〃Twigs；〃　he　said　gravely；　〃twigs；　and　a　total　stranger　with　his　head　cut　off；　that　is　all　there　is　on　this　lawn。〃　　　　　There　was　an　almost　creepy　stillness；　and　then　the　unnerved　Galloway　called　out　sharply：　　　　　〃Who's　that！　　Who's　that　over　there　by　the　garden　wall！〃　　　　　A　small　figure　with　a　foolishly　large　head　drew　waveringly　near　them　in　the　moonlit　haze；　looked　for　an　instant　like　a　goblin；　but　turned　out　to　be　the　harmless　little　priest　whom　they　had　left　in　the　drawing…room。　　　　　〃I　say；〃　he　said　meekly；　〃there　are　no　gates　to　this　garden；　do　you　know。〃　　　　　Valentin's　black　brows　had　come　together　somewhat　crossly；　as　they　did　on　principle　at　the　sight　of　the　cassock。　　But　he　was　far　too　just　a　man　to　deny　the　relevance　of　the　remark。　　〃You　are　right；〃　he　said。　　〃Before　we　find　out　how　he　came　to　be　killed；　we　may　have　to　find　out　how　he　came　to　be　here。　　Now　listen　to　me；　gentlemen。　　If　it　can　be　done　without　prejudice　to　my　position　and　duty；　we　shall　all　agree　that　certain　distinguished　names　might　well　be　kept　out　of　this。　　There　are　ladies；　gentlemen；　and　there　is　a　foreign　ambassador。　　If　we　must　mark　it　down　as　a　crime；　then　it　must　be　followed　up　as　a　crime。　　But　till　then　I　can　use　my　own　discretion。　　I　am　the　head　of　the　police；　I　am　so　public　that　I　can　afford　to　be　private。　　Please　Heaven；　I　will　clear　everyone　of　my　own　guests　before　I　call　in　my　men　to　look　for　anybody　else。　Gentlemen；　upon　your　honour；　you　will　none　of　you　leave　the　house　till　tomorrow　at　noon；　there　are　bedrooms　for　all。　　Simon；　I　think　you　know　where　to　find　my　man；　Ivan；　in　the　front　hall；　he　is　a　confidential　man。　　Tell　him　to　leave　another　servant　on　guard　and　come　to　me　at　once。　　Lord　Galloway；　you　are　certainly　the　best　person　to　tell　the　ladies　what　has　happened；　and　prevent　a　panic。　They　also　must　stay。　　Father　Brown　and　I　will　remain　with　the　body。〃　　　　　When　this　spirit　of　the　captain　spoke　in　Valentin　he　was　obeyed　like　a　bugle。　　Dr。　Simon　went　through　to　the　armoury　and　routed　out　Ivan；　the　public　detective's　private　detective。　　Galloway　went　to　the　drawing…room　and　told　the　terrible　news　tactfully　enough；　so　that　by　the　time　the　company　assembled　there　the　ladies　were　already　startled　and　already　soothed。　　Meanwhile　the　good　priest　and　the　good　atheist　stood　at　the　head　and　foot　of　the　dead　man　motionless　in　the　moonlight；　like　symbolic　statues　of　their　two　philosophies　of　death。　　　　　Ivan；　the　confidential　man　with　the　scar　and　the　moustaches；　came　out　of　the　house　like　a　cannon　ball；　and　came　racing　across　the　lawn　to　Valentin　like　a　dog　to　his　master。　　His　livid　face　was　quite　lively　with　the　glow　of　this　domestic　detective　story；　and　it　was　with　almost　unpleasant　eagerness　that　he　asked　his　master's　permission　to　examine　the　remains。　　　　　〃Yes；　look；　if　you　like；　Ivan；〃　said　Valentin；　〃but　don't　be　long。　　We　must　go　in　and　thrash　this　out　in　the　house。〃　　　　　Ivan　lifted　the　head；　and　then　almost　let　it　drop。　　　　　〃Why；〃　he　gasped；　〃it'sno；　it　isn't；　it　can't　be。　　Do　you　know　this　man；　sir？〃　　　　　〃No；〃　said　Valentin　indifferently；　〃we　had　better　go　inside。〃　　　　　Between　them　they　carried　the　corpse　to　a　sofa　in　the　study；　and　then　all　made　their　way　to　the　drawing…room。　　　　　The　detective　sat　down　at　a　desk　quietly；　and　even　without　hesitation；　but　his　eye　was　the　iron　eye　of　a　judge　at　assize。　　He　made　a　few　rapid　notes　upon　paper　in　front　of　him；　and　then　said　shortly：　〃Is　everybody　here？〃　　　　　〃Not　Mr。　Brayne；〃　said　the　Duchess　of　Mont　St。　Michel；　looking　round。　　　　　〃No；〃　said　Lord　Galloway　in　a　hoarse；　harsh　voice。　　〃And　not　Mr。　Neil　O'Brien；　I　fancy。　　I　saw　that　gentleman　walking　in　the　garden　when　the　corpse　was　still　warm。〃　　　　　〃Ivan；〃　said　the　detective；　〃go　and　fetch　Commandant　O'Brien　and　Mr。　Brayne。　　Mr。　Brayne；　I　know；　is　finishing　a　cigar　in　the　dining…room；　Commandant　O'Brien；　I　think；　is　walking　up　and　down　the　conservatory。　　I　am　not　sure。〃　　　　　The　faithful　attendant　flashed　from　the　room；　and　before　anyone　could　stir　or　speak　Valentin　went　on　with　the　same　soldierly　swiftness　of　exposition。　　　　　〃Everyone　here　knows　that　a　dead　man　has　been　found　in　the　garden；　his　head　cut　clean　from　his　body。　　Dr。　Simon；　you　have　examined　it。　　Do　you　think　that　to　cut　a　man's　throat　like　that　would　need　great　force？　　Or；　perhaps；　only　a　very　sharp　knife？〃　　　　　〃I　should　say　that　it　could　not　be　done　with　a　knife　at　all；〃　said　the　pale　doctor。　　　　　〃Have　you　any　thought；〃　resumed　Valentin；　〃of　a　tool　with　which　it　could　be　done？〃　　　　　〃Speaking　within　modern　probabilities；　I　really　haven't；〃　said　the　doctor；　arching　his　painful　brows。　　〃It's　not　easy　to　hack　a　neck　through　even　clumsily；　and　this　was　a　very　clean　cut。　　It　could　be　done　with　a　battle…axe　or　an　old　headsman's　axe；　or　an　old　two…handed　sword。〃　　　　　〃But；　good　heavens！〃　cried　the　Duchess；　almost　in　hysterics；　〃there　aren't　any　two…handed　swords　and　battle…axes　round　here。〃　　　　　Valentin　was　still　busy　with　the　paper　in　front　of　him。　　〃Tell　me；〃　he　said；　still　writing　rapidly；　〃could　it　have　been　done　with　a　long　French　cavalry　sabre？〃　　　　　A　low　knocking　came　at　the　door；　which；　for　some　unreasonable　reason；　curdled　everyone's　blood　like　the　knocking　in　Macbeth。　Amid　that　frozen　silence　Dr。　Simon　managed　to　say：　〃A　sabre　yes；　I　suppose　it　could。〃　　　　　〃Thank　you；〃　said　Valentin。　　〃Come　in；　Ivan。〃　　　　　The　confidential　Ivan　opened　the　door　and　ushered　in　Commandant　Neil　O'Brien；　whom　he　had　found　at　last　pacing　the　garden　again。　　　　　The　Irish　officer　stood　up　disordered　and　defiant　on　the　threshold。　　〃What　do　you　want　with　me？〃　he　cried。　　　　　〃Please　sit　down；〃　said　Valentin　in　pleasant；　level　tones。　〃Why；　you　aren't　wearing　your　sword。　　Where　is　it？〃　　　　　〃I　left　it　on　the　library　table；〃　said　O'Brien；　his　brogue　deepening　in　his　disturbed　mood。　　〃It　was　a　nuisance；　it　was　getting〃　　　　　〃Ivan；〃　said　Valentin；　〃please　go　and　get　the　Commandant's　sword　from　the　library。〃　　Then；　as　the　servant　vanished；　〃Lord　Galloway　says　he　saw　you　leaving　the　garden　just　before　he　found　the　corpse。　　What　were　you　doing　in　the　garden？〃　　　　　The　Commandant　flung　himself　recklessly　into　a　chair。　　〃Oh；〃　he　cried　in　pure　Irish；　〃admirin'　the　moon。　　Communing　with　Nature；　me　bhoy。〃　　　　　A　heavy　silence　sank　and　endured；　and　at　the　end　of　it　came　again　that　trivial　and　terrible　knocking。　　Ivan　reappeared；　carrying　an　empty　steel　scabbard。　　〃This　is　all　I　can　find；〃　he　said。　　　　　〃Put　it　on　the　table；〃　said　Valentin；　without　looking　up。　　　　　There　was　an　inhuman　silence　in　the　room；　like　that　sea　of　inhuman　silence　round　the　dock　of　the　condemned　murderer。　　The　Duchess's　weak　exclamations　had　long　ago　died　away。　　Lord　Galloway's　swollen　hatred　was　satisfied　and　even　sobered。　　The　voice　that　came　was　quite　unexpected。　　　　　〃I　think　I　can　tell　you；〃　cried　Lady　Margaret；　in　that　clear；　quivering　voice　with　which　a　courageous　woman　speaks　publicly。　　〃I　can　tell　you　what　Mr。　O'Brien　was　doing　in　the　garden；　since　he　is　bound　to　silence。　　He　was　asking　me　to　marry　him。　　I　refused；　I　said　in　my　family　circumstances　I　could　give　him　nothing　but　my　respect。　　He　was　a　little　angry　at　that；　he　did　not　seem　to　think　much　of　my　respect。　　I　wonder；〃　she　added；　with　rather　a　wan　smile；　〃if　he　will　care　at　all　for　it　now。　　For　I　offer　it　him　now。　　I　will　swear　anywhere　that　he　never　did　a　thing　like　this。〃　　　　　Lord　Galloway　had　edged　up　to　his　daughter；　and　was　intimidating　her　in　what　he　imagined　to　be　an　undertone。　　〃Hold　your　tongue；　Maggie；〃　he　said　in　a　thunderous　whisper。　　〃Why　should　you　shield　the　fellow？　　Where's　his　sword？　　Where's　his　confounded　cavalry〃　　　　　He　stopped　because　of　the　singular　stare　with　which　his　daughter　was　regarding　him；　a　look　that　was　indeed　a　lurid　magnet　for　the　whole　group。　　　　　〃You　old　fool！〃　she　said　in　a　low　voice　without　pretence　of　piety；　〃what　do　you　suppose　you　are　trying　to　prove？　　I　tell　you　this　man　was　innocent　while　with　me。　　But　if　he　wasn't　innocent；　he　was　still　with　me。　　If　he　murdered　a　man　in　the　garden；　who　was　it　who　must　have　seenwho　must　at　least　have　known？　　Do　you　hate　Neil　so　much　as　to　put　your　own　daughter〃　　　　　Lady　Galloway　screamed。　　Everyone　else　sat　tingling　at　the　touch　of　those　satanic　tragedies　that　have　been　between　lovers　before　now。　　They　saw　the　proud；　white　face　of　the　Scotch　aristocrat　and　her　lover；　the　Irish　adventurer；　like　old　portraits　in　a　dar