A few weeks later I went hunting with Paul. He had beenpromising me for some time that I should have the pleasureof shooting over a wonderful dog—the most wonderfuldog， in fact， that ever man shot over， so he averred， andcontinued to aver till my curiosity was aroused. But on themorning in question I was disappointed， for there was nodog in evidence.
“Don’t see him about，” Paul remarked unconcernedly，and we set off across the fields.
I could not imagine， at the time， what was ailing me， butI had a feeling of some impending and deadly illness. Mynerves were all awry， and， from the astounding tricks theyplayed me， my senses seemed to have run riot. Strangesounds disturbed me. At times I heard the swish-swishof grass being shoved aside， and once the patter of feetacross a patch of stony ground.
“Did you hear anything， Paul？” I asked once.
But he shook his head， and thrust his feet steadilyforward.
While climbing a fence， I heard the low， eager whine ofa dog， apparently from within a couple of feet of me； buton looking about me I saw nothing.
I dropped to the ground， limp and trembling.
“Paul，” I said， “we had better return to the house. I amafraid I am going to be sick.”
“Nonsense， old man，” he answered. “The sunshine hasgone to your head like wine. You’ll be all right. It’s famousweather.”
But， passing along a narrow path through a clump ofcottonwoods， some object brushed against my legs and Istumbled and nearly fell. I looked with sudden anxiety atPaul.
“What’s the matter？” he asked. “Tripping over your ownfeet？”
I kept my tongue between my teeth and plodded on，though sore perplexed and thoroughly satisfied that someacute and mysterious malady had attacked my nerves. Sofar my eyes had escaped； but， when we got to the openfields again， even my vision went back on me. Strangeflashes of vari-colored， rainbow light began to appear anddisappear on the path before me. Still， I managed to keepmyself in hand， till the vari-colored lights persisted fora space of fully twenty seconds， dancing and flashing incontinuous play. Then I sat down， weak and shaky.
“It’s all up with me，” I gasped， covering my eyes with myhands. “It has attacked my eyes. Paul， take me home.”
But Paul laughed long and loud. “What did I tell you？—the most wonderful dog， eh？ Well， what do you think？”
He turned partly from me and began to whistle. I heardthe patter of feet， the panting of a heated animal， and theunmistakable yelp of a dog. Then Paul stooped down andapparently fondled the empty air.
“Here！ Give me your fist.”
And he rubbed my hand over the cold nose and jowlsof a dog. A dog it certainly was， with the shape and thesmooth， short coat of a pointer.
Suffice to say， I speedily recovered my spirits and control.
Paul put a collar about the animal’s neck and tied hishandkerchief to its tail. And then was vouchsafed usthe remarkable sight of an empty collar and a wavinghandkerchief cavorting over the fields. It was somethingto see that collar and handkerchief pin a bevy of quail ina clump of locusts and remain rigid and immovable till wehad flushed the birds.
Now and again the dog emitted the vari-colored lightflashesI have mentioned. The one thing， Paul explained，which he had not anticipated and which he doubted couldbe overcome.
“They’re a large family，” he said， “these sun dogs， winddogs， rainbows， halos， and parhelia. They are producedby refraction of light from mineral and ice crystals， frommist， rain， spray， and no end of things； and I am afraidthey are the penalty I must pay for transparency. I escapedLloyd’s shadow only to fetch up against the rainbow flash.”
A couple of days later， before the entrance to Paul’slaboratory， I encountered a terrible stench. So overpoweringwas it that it was easy to discover the source： a mass ofputrescent matter on the doorstep which in generaloutlines resembled a dog.
Paul was startled when he investigated my find. It washis invisible dog， or rather， what had been his invisibledog， for it was now plainly visible. It had been playingabout but a few minutes before in all health and strength.
Closer examination revealed that the skull had beencrushed by some heavy blow. While it was strange that theanimal should have been killed， the inexplicable thing wasthat it should so quickly decay.
“The reagents I injected into its system were harmless，”
Paul explained. “Yet they were powerful， and it appearsthat when death comes they force practically instantaneousdisintegration. Remarkable！ Most remarkable！ Well， theonly thing is not to die. They do not harm so long as onelives. But I do wonder who smashed in that dog’s head.”
Light， however， was thrown upon this when a frightenedhousemaid brought the news that Gaffer Bedshaw had thatvery morning， not more than an hour back， gone violentlyinsane， and was strapped down at home， in the huntsman’slodge， where he raved of a battle with a ferocious andgigantic beast that he had encountered in the Tichlornepasture. He claimed that the thing， whatever it was， wasinvisible， that with his own eyes he had seen that it wasinvisible； wherefore his tearful wife and daughters shooktheir heads， and wherefore he but waxed the more violent，and the gardener and the coachman tightened the strapsby another hole.
Nor， while Paul Tichlorne was thus successfullymastering the problem of invisibility， was Lloyd Inwooda whit behind. I went over in answer to a message ofhis to come and see how he was getting on. Now hislaboratory occupied an isolated situation in the midstof his vast grounds. It was built in a pleasant little glade，surrounded on all sides by a dense forest growth， and wasto be gained by way of a winding and erratic path. But Ihave travelled that path so often as to know every foot ofit， and conceive my surprise when I came upon the gladeand found no laboratory. The quaint shed structure withits red sandstone chimney was not. Nor did it look as ifit ever had been. There were no signs of ruin， no debris，nothing.
