But the court was empty. As I stood there， gaping openmouthed，a tennis ball struck me on the arm， and as Iturned about， another whizzed past my ear. For aught Icould see of my assailant， they came whirling at me fromout of space， and right well was I peppered with them. Butwhen the balls already flung at me began to come back fora second whack， I realized the situation. Seizing a racquetand keeping my eyes open， I quickly saw a rainbow flashappearing and disappearing and darting over the ground. Itook out after it， and when I laid the racquet upon it for ahalf-dozen stout blows， Paul’s voice rang out：
“Enough！ Enough！ Oh！ Ouch！ Stop！ You’re landing onmy naked skin， you know！ Ow！ O-w-w！ I’ll be good！ I’ll begood！ I only wanted you to see my metamorphosis，” hesaid ruefully， and I imagined he was rubbing his hurts.
A few minutes later we were playing tennis—a handicapon my part， for I could have no knowledge of his positionsave when all the angles between himself， the sun， andme， were in proper conjunction. Then he flashed， andonly then. But the flashes were more brilliant than therainbow—purest blue， most delicate violet， brightestyellow， and all the intermediary shades， with the scintillantbrilliancy of the diamond， dazzling， blinding， iridescent.
But in the midst of our play I felt a sudden cold chill，reminding me of deep mines and gloomy crypts， such achill as I had experienced that very morning. The nextmoment， close to the net， I saw a ball rebound in midairand empty space， and at the same instant， a score offeet away， Paul Tichlorne emitted a rainbow flash. It couldnot be he from whom the ball had rebounded， and withsickening dread I realized that Lloyd Inwood had comeupon the scene. To make sure， I looked for his shadow，and there it was， a shapeless blotch the girth of his body，（the sun was overhead）， moving along the ground. Iremembered his threat， and felt sure that all the long yearsof rivalry were about to culminate in uncanny battle.
I cried a warning to Paul， and heard a snarl as of a wildbeast， and an answering snarl. I saw the dark blotch moveswiftly across the court， and a brilliant burst of varicoloredlight moving with equal swiftness to meet it； andthen shadow and flash came together and there was thesound of unseen blows. The net went down before myfrightened eyes. I sprang toward the fighters， crying：
“For God’s sake！”
But their locked bodies smote against my knees， and Iwas overthrown.
“You keep out of this， old man！” I heard the voice ofLloyd Inwood from out of the emptiness. And then Paul’svoice crying， “Yes， we’ve had enough of peacemaking！”
From the sound of their voices I knew they hadseparated. I could not locate Paul， and so approached theshadow that represented Lloyd. But from the other sidecame a stunning blow on the point of my jaw， and I heardPaul scream angrily， “Now will you keep away？”
Then they came together again， the impact of theirblows， their groans and gasps， and the swift flashings andshadow-movings telling plainly of the deadliness of thestruggle.
I shouted for help， and Gaffer Bedshaw came runninginto the court. I could see， as he approached， that hewas looking at me strangely， but he collided with thecombatants and was hurled headlong to the ground. Withdespairing shriek and a cry of “O Lord， I’ve got ’em！” hesprang to his feet and tore madly out of the court.
I could do nothing， so I sat up， fascinated and powerless，and watched the struggle. The noonday sun beat downwith dazzling brightness on the naked tennis court. Andit was naked. All I could see was the blotch of shadow andthe rainbow flashes， the dust rising from the invisible feet，the earth tearing up from beneath the straining foot-grips，and the wire screen bulge once or twice as their bodieshurled against it. That was all， and after a time even thatceased. There were no more flashes， and the shadow hadbecome long and stationary； and I remembered their setboyish faces when they clung to the roots in the deepcoolness of the pool.
They found me an hour afterward. Some inkling ofwhat had happened got to the servants and they quittedthe Tichlorne service in a body. Gaffer Bedshaw neverrecovered from the second shock he received， and isconfined in a madhouse， hopelessly incurable. The secretsof their marvellous discoveries died with Paul and Lloyd，both laboratories being destroyed by grief-strickenrelatives. As for myself， I no longer care for chemicalresearch， and science is a tabooed topic in my household.
I have returned to my roses. Nature’s colors are goodenough for me.
