d　of　flame；　and　motioned　the　American　to　come　to　him。
  Johnston　promptly；　but　not　without　many　misgivings；　obeyed　his　signal。　〃What　are　you　up　to？〃　asked　he；　as　the　Alphian　assisted　him　to　rise　from　his　hands　and　knees。
  Branasko　touched　the　machine　and　smiled。　His　face　was　shining　with　enthusiasm。
  〃The　question　of　our　returning　to　Alpha　is　settled；〃　he　said　sententiously。
  〃How？〃
  〃We　can　go　in　this。〃
  〃Can　you　manage　it？〃
  〃Easily；　that　fellow　must　have　been　drunk；　the　machine　is　in　good　order；　I　think。〃
  〃When　do　you　propose　to　start？〃　and　the　American　eyed　the　funeral…　car　dubiously。
  〃The　night　is　before　us；　we　could　not　get　a　better　time。〃　As　he　spoke　he　entered　the　car　and　laid　his　hand　on　the　wheel。　Johnston；　obeying　his　nod；　followed；　shuddering　as　he　remarked　the　traces　of　blood　on　the　floor。
  〃All　right！〃　Branasko　turned　the　wheel　slowly；　and　the　wings　outside　began　to　flap；　and　the　car　mounted　into　the　air　like　a　startled　bird　and　flew　out　quickly　over　the　pit。
  Branasko　bit　his　lip；　and　Johnston　heard　him　stifle　an　exclamation　of　impatience。　As　for　the　American；　he　was　at　once　thrilled　and　fascinated　by　the　awful　sight　below；　he　could　now　see　beneath　the　overhanging　mouth　of　the　pit；　and　look　far　down　into　a　boundless　lake　of　molten　matter　that　seemed　as　restless　as　an　ocean　in　a　storm。
  Then　the　air　became　so　hot　he　could　hardly　breathe。　He　looked　at　the　Alphian　in　alarm。　The　latter　was　whirling　the　wheel　first　one　way　and　then　another　with　a　startled　look　of　fear　in　his　eyes；　and　then　Johnston　noticed　that　the　walls　of　the　pit　were　rising　about　them；　and　the　black　canopy　overhead　rapidly　receding。
  They　were　sinking　down　into　the　fire。
  Almost　wild　with　terror；　the　American　sprang　toward　the　wheel；　but　Branasko　pushed　him　away　roughly。
  〃Stand　back；〃　he　ordered　gruffly。　〃It　is　the　heat；　let　me　alone！〃
  The　American　sank　into　his　seat。　The　heat　became　more　and　more　intense。　Both　men　were　purple　in　the　face；　and　the　perspiration　was　rolling　from　their　bodies　in　streams。　Down　sank　the　machine。
  〃I　can't　manage　it；〃　said　Branasko　hoarsely；　〃we'd　as　well　give　up。〃　Just　then　Johnston　noticed　the　mouth　of　a　cave　behind　Branasko。
  〃Look；〃　he　cried；　〃can't　we　get　into　it？〃
  Branasko　looked　over　his　shoulder；　and；　as　he　saw　the　cave；　he　uttered　a　glad　cry。　He　quickly　turned　the　wheel　and　drew　out　a　lever　at　his　right。　The　machine　obeyed　instantly；　it　swerved　round　suddenly　and　dived　into　the　cave。　The　cool　air　soon　revived　them；　and　Branasko　had　little　trouble　in　bringing　the　car　to　a　resting…　place　on　the　rocky　floor　of　the　cave。　Before　them　hung　impenetrable　darkness；　behind　a　curtain　of　red　light。
  〃We　are　in　a　pretty　pickle　now；〃　said　Johnston　despondently；　as　they　alighted　from　the　car。
  〃Nothing　to　do　but　to　make　the　best　of　it；〃　sighed　Branasko。
  〃Perhaps　this　cave　may　lead　out　into　some　place　of　safety。〃
  Johnston's　eyes　had　become　somewhat　accustomed　to　the　gloom；　and　he　began　to　peer　into　the　darkness。
  〃I　see　a　light；〃　he　exclaimed；　〃it　cannot　be　a　reflection　from　the　fire　in　the　pit；　for　it　is　whiter。〃
  The　Alphian　gazed　at　it　steadily　for　a　moment；　then　he　said　decidedly：　〃We　must　go　and　see　what　it　is。〃　Without　another　word　he　started　toward　the　white；　star…like　spot；　sliding　his　hand　over　the　rocky　wall；　and　springing　over　a　fissure　in　the　floor。
  Gradually　the　light　grew　brighter；　till；　as　they　suddenly　rounded　a　cliff；　a　grand　sight　burst　upon　their　view。　They　found　themselves　in　a　vast　dome…shaped　cavern；　thousands　of　yards　in　diameter　and　height。　And　almost　in　the　centre　of　the　floor；　from　a　red　and　purple　mound　of　cooling　lava；　leapt　a　white　stream　of　molten　matter　from　the　floor　to　the　dome。　And　in　the　black　dome；　where　the　lava　turned　to　molten　spray；　hung　countless　stalactites　of　every　color　known　to　the　artistic　eye。　And　from　the　foot　of　the　fountain　ran　a　tortuous　rivulet　that　lighted　the　walls　and　roof　of　a　narrow　chamber　that　extended　for　miles　down　toward　the　bowels　of　the　earth。
  Branasko　was　delighted。
  〃The　king　does　not　know　of　this；〃　he　declared；　〃else　he　would　make　it　accessible　to　his　people；　and　call　it　one　of　the　wonders　of　Alpha。　By　accidentally　sinking　into　the　pit　we　have　discovered　it。　But；〃　he　concluded；　〃we　must　at　once　try　to　find　some　way　out　other　than　that　by　which　we　came。〃
  They　turned　from　the　beautiful　fountain；　and；　holding　to　each　other's　hands；　and　aided　by　the　light　behind　them；　they　stumbled　laboriously　through　the　semi…darkness。　Branasko's　ears　were　very　acute。　He　paused　to　listen。
  〃Hark　ye！〃　he　cautioned。
  The　combined　roar　of　the　pit　and　the　fountain　of　lava　had　sunk　to　a　low　murmur；　but　ahead　of　them　they　now　heard　a　rushing　sound　like　a　distant　tornado。
  〃Come　on；〃　said　the　Alphian；　and　he　drew　his　companion　after　him　with　an　eagerness　the　American　was　slow　to　understand。　The　light　in　the　cavern　gradually　grew　brighter。　By　a　circuitous　route　they　were　again　approaching　the　pit　of　fire；　though　it　was　still　hidden　from　sight。
  Finally　they　reached　a　point　where　the　wind　was　blowing　stiffly；　and　further　on　a　volume　of　cold　spray　suddenly　dashed　upon　them　and　wet　them　to　the　skin。　And　when　their　eyes　had　become　accustomed　to　the　rolling　mist；　they　saw　a　great　lake；　and　pouring　into　it　from　high　above　was　a　mighty　waterfall。
  〃Mercy！〃　ejaculated　the　Alphian；　in　great　alarm。　〃If　this　is　salt　water　we　are　lost。　All　Alpha　will　come　to　an　end！〃
  〃What　do　you　mean？〃　And　Johnston　wondered　if　Branasko's　trials　and　struggle　could　have　turned　his　brain。
  〃If　it　be　salt　water；　then　it　has　broken　in　from　the　ocean　above　Alpha；〃　he　explained。　〃The　king　has　often　said　that　not　a　drop　of　the　ocean　has　ever　entered　the　great　cavern。〃
  Branasko　stooped　and　wet　his　hand　in　a　little　pool　at　his　feet。　〃I　am　almost　afraid　to　taste　it；〃　said　he；　holding　his　hand　near　his　mouth。　〃It　would　settle　all　our　fates。〃　He　waited　a　moment　and　then　touched　his　fingers　to　his　tongue。
  〃Salt！〃　That　was　all　he　said　for　several　moments。　He　folded　his　arms　and　looked　mutely　toward　the　boiling　lake。　Presently　he　raised　his　eyes　to　the　great　hole　in　the　roof；　and　groaned：　〃The　break　is　gradually　widening。　These　stones　are　freshly　broken；　and　the　great　bowl　is　filling。〃
  〃It　will　fill　all　Alpha　with　water　and　drown　every　soul　in　it；〃　added　the　terrified　American。
  〃That；　however；　is　not　the　most　immediate　danger；〃　said　Branasko　wisely。　〃They　would　first　suffocate；　and　later　their　bodies　would　be　swallowed　up　in　the　stomach　of　the　earth。〃
  〃What　do　you　mean？〃
  Branasko　shrugged　his　shoulders。　〃As　soon　as　this　bowl　is　filled　with　water；　which　would　not　take　many　hours；　it　would　run　over　into　the　lake　of　fire　and　produce　an　explosion　that　would　rend　Alpha　from　end　to　end。〃
  〃Who　knows；　it　might　turn　the　whole　Atlantic　into　the　centre　of　the　earth；　and　destroy　the　entire　earth。〃　But　Branasko　was　unable　to　grasp　the　full　magnitude　of　the　remark；　for　to　him　the　world　was　simply　a　vast　cavern　lighted　by　human　ingenuity。　He　fastened　a　narrow　splinter　of　stone　upright　in　the　shallow　water　at　his　eet；　and；　lying　down　on　his　stomach　with　his　eyes　close　to　it；　he　studied　it　for　several　minutes。　When　he　got　up；　a　desperate　gleam　was　in　his　dark　eyes。
  〃It　is　rising　fast；〃　he　said。　〃We　must　attempt　to　get　to　the　capitol　and　warn　the　king。　It　is　possible　that　he　may　be　able　to　stop　the　opening。　The　only　thing　left　to　us　is　to　try　our　machine　again。〃
  Johnston　found　it　hard　to　keep　pace　with　him　as　he　bounded　out　of　the　mist　and　on　toward　the　faint　glow　ahead。　Reaching　the　flying　machine　Branasko　entered　it　and　turned　on　a　small　electric　light。
  〃Ah；〃　he　grunted　with　satisfaction；　〃I　have　found　a　light。　I　can　now　see　what　is　the　matter　with　it。〃
  Johnston　stood　outside　and　heard　him　hammering　on　the　metal　parts　in　the　car；　and　became　so　absorbed　in　thinking　of　the　peril　of　their　position　that　he　was　startled　when　Branasko　cried　out　to　him：〃All　right。　I　think　we　can　make　it　do；　a　pin　has　lost　out；　but　perhaps　I　can　hold　the　piece　in　place　with　my　foot。　If　only　we　can　stand　the　heat　of　the　pit　long　enough　to　rise　above　it；　we　may　escape。〃
  Johnston　followed　him　into　the　car。　Branasko　seated　himself　firmly　and　gave　the　wheel　a　little　turn。　Slowly　the　machine　rose。　〃See！〃　cried　Branasko；　〃it　is　under　control。　〃We　must　not　be　too　hasty。　Now　for　the　pit！〃
  The　heart　of　the　American　was　in　his　mouth　as　the　long　black　wings　waved　up　and　down　and　the　air…ship；　like　some　live　thing；　shuddered　and　swept　gracefully　out　of　the　mouth　of　the　cave　into　the　glare　and　heat　of　the　pit。
  〃Hold　your　breath！〃　yelled　Branasko；　and　he　bent　lower　into　the　car　to　escape　the　shower　of　hot　ashes　that　was　falling　about　them。　Far　out　over　the　lake　in　a　straight　line　they　glided；　and　there　came　to　a　sudden　halt。　Johnston's　eyes　were　glued　on　his　companion's　face。　Branasko　sat　doubled　up；　every　muscle　drawn；　his　eyes　bulging　from　their　sockets。　Would　he　be　strong　enough？　To　Johnston　everything　seemed　in　a　whirl。　The　walls　of　the　pit　were　rising　around　them。
  Chapter　XVI。
  Thorndyke　went　down　into　his　chambers　to　make　his　toilet　and　was　ready　to　leave　when　there　was　a　soft　rap　on　his　door。　He　opened　it；　and　to　his　surprise　saw　Bernardino　modestly　draw　hersel