edmotionless,asiftheyhadbeenturnedtobronze,listeningintentlywithexpressionsofterrorupontheirfaces.
"Whatisit,then?"Iasked.
"Drums,"saidLordJohn,carelessly"wardrums.Ihaveheardthembefore."
"Yes,sir,wardrums,"saidGomez,thehalf-breed."WildIndians,bravos,notmansostheywatchuseverymileofthewaykillusiftheycan."
"Howcantheywatchus?"Iasked,gazingintothedark,motionlessvoid.
Thehalf-breedshruggedhisbroadshoulders.
"TheIndiansknow.Theyhavetheirownway.Theywatchus.Theytalkthedrumtalktoeachother.Killusiftheycan."
Bytheafternoonofthatday—mypocketdiaryshowsmethatitwasTuesday,August18th—atleastsixorsevendrumswerethrobbingfromvariouspoints.Sometimestheybeatquickly,sometimesslowly,sometimesinobviousquestionandanswer,onefartotheeastbreakingoutinahighstaccatorattle,andbeingfollowedafterapausebyadeeprollfromthenorth.Therewassomethingindescribablynerve-shakingandmenacinginthatconstantmutter,whichseemedtoshapeitselfintotheverysyllablesofthehalf-breed,endlesslyrepeated,"Wewillkillyouifwecan.Wewillkillyouifwecan."Nooneevermovedinthesilentwoods.AllthepeaceandsoothingofquietNaturelayinthatdarkcurtainofvegetation,butawayfrombehindtherecameevertheonemessagefromourfellow-man."Wewillkillyouifwecan,"saidthemenintheeast."Wewillkillyouifwecan,"saidthemeninthenorth.
Alldaythedrumsrumbledandwhispered,whiletheirmenacereflecteditselfinthefacesofourcoloredcompanions.Eventhehardy,swaggeringhalf-breedseemedcowed.Ilearned,however,thatdayonceforallthatbothSummerleeandChallengerpossessedthathighesttypeofbravery,thebraveryofthescientificmind.TheirswasthespiritwhichupheldDarwinamongthegauchosoftheArgentineorWallaceamongthehead-huntersofMalaya.ItisdecreedbyamercifulNaturethatthehumanbraincannotthinkoftwothingssimultaneously,sothatifitbesteepedincuriosityastoscienceithasnoroomformerelypersonalconsiderations.AlldayamidthatincessantandmysteriousmenaceourtwoProfessorswatchedeverybirduponthewing,andeveryshrubuponthebank,withmanyasharpwordycontention,whenthesnarlofSummerleecamequickuponthedeepgrowlofChallenger,butwithnomoresenseofdangerandnomorereferencetodrum-beatingIndiansthanifthey