"Are you sure?" The man stared at us, one after another. Then he said: "What are you looking for in Black Bayou?" "Something very curious, very strange, very unusual. So strange and unusual, in fact, that the great Zooelogical Society of the Bronx in New York has sent me down here at the head of this expedition to search the forests of Black Bayou." "For what?" he demanded, in a dull, accentless voice. "For a totally new species of human being, Grue. I wish to catch one and take it back to New York in that folding cage." His green eyes had grown narrow as though sun-dazzled. Kemper had stepped behind us into the woods and was now busy setting up the folding cage. Grue remained motionless. "I am going to offer you," I said, "the sum of one thousand dollars in gold if you can guide us to a spot where we may see this hitherto unknown species--a creature which is apparently a man but which has, in the back of his head, a _third eye_--" I paused in amazement: Grue's cheeks had suddenly puffed out and were quivering; and from the corners of his slitted mouth he was emitting a whimpering sound like the noise made by a low-circling pigeon. "Grue!" I cried. "What's the matter with you?" "What is _he_ doing?" screamed Grue, quivering from head to foot, but not turning around. "Who?" I cried. "The man behind me!" "Professor Kemper? He's setting up the folding cage--" With a screech that raised my hair, Grue whipped out his murderous knife and _hurled himself backward_ at Kemper, but the latter shrank aside behind the partly erected cage, and Grue whirled around, snarling, hacking, and even biting at the wood frame and steel bars. And then occurred a thing so horrid that it sickened me to the pit of my stomach; for the man's sagging straw hat had fallen off, and there, in the back of his head, through the coarse, black, ratty hair, I saw a glassy eye glaring at me. "Kemper!" I shouted. "He's got a third eye! He's one of them! Knock him flat with your riflestock!" And I seized a shot-gun from the top of the baggage bundle on the ground beside me, and leaped at Grue, aiming a terrific blow at him. [Illustration: "'Kemper!' I shouted.... 'He is one of them! Knock him flat with your riflestock!'"] But the glassy eye in the back of his head was watching me between the clotted strands of hair, and he dodged both Kemper and me, swinging his heavy knife in circles and glaring at us both out of the front and back of his head. Kemper seized him by his arm, but Grue's shirt came off, and I saw his entire body was as furry as an ape's. And all the while he was snapping at us and leaping hither and thither to avoid our blows; and from the corners of his puffed cheeks he whined and whimpered and mewed through the saliva foam. "Keep him from the water!" I panted, following him with clubbed shot-gun; and as I advanced I almost stepped on a soiled heap of foulness--the dead buzzard which he had caught and worried to death with his teeth.