"But we did see one thing that registered. We came to that same building Leroy and I had entered earlier--the one with the three eyes in it. Well, we were a little shaky about going in there, but Tweel twittered and trilled and kept saying, 'Yes, yes, yes!' so we followed him, staring nervously about for the thing that had watched us. However, that hall was just like the others, full of murmurs and slithering noises and shadowy things slipping away into corners. If the three-eyed creature were still there, it must have slunk away with the others. "Tweel led us along the wall; his light showed a series of little alcoves, and in the first of these we ran into a puzzling thing--a very weird thing. As the light flashed into the alcove, I saw first just an empty space, and then, squatting on the floor, I saw--it! A little creature about as big as a large rat, it was, gray and huddled and evidently startled by our appearance. It had the queerest, most devilish little face!--pointed ears or horns and satanic eyes that seemed to sparkle with a sort of fiendish intelligence. "Tweel saw it, too, and let out a screech of anger, and the creature rose on two pencil-thin legs and scuttled off with a half-terrified, half defiant squeak. It darted past us into the darkness too quickly even for Tweel, and as it ran, something waved on its body like the fluttering of a cape. Tweel screeched angrily at it and set up a shrill hullabaloo that sounded like genuine rage. "But the thing was gone, and then I noticed the weirdest of imaginable details. Where it had squatted on the floor was--a book! It had been hunched over a book! "I took a step forward; sure enough, there was some sort of inscription on the pages--wavy white lines like a seismograph record on black sheets like the material of Tweel's pouch. Tweel fumed and whistled in wrath, picked up the volume and slammed it into place on a shelf full of others. Leroy and I stared dumbfounded at each other. "Had the little thing with the fiendish face been reading? Or was it simply eating the pages, getting physical nourishment rather than mental? Or had the whole thing been accidental? "If the creature were some rat-like pest that destroyed books, Tweel's rage was understandable, but why should he try to prevent an intelligent being, even though of an alien race, from _reading_--if it _was_ reading? I don't know; I did notice that the book was entirely undamaged, nor did I see a damaged book among any that we handled. But I have an odd hunch that if we knew the secret of the little cape-clothed imp, we'd know the mystery of the vast abandoned city and of the decay of Martian culture.