This last painting by the door, for instance. It showed the translucent city again, with approximately the same details--but with a barely-perceptible dimming of the red sunlight, a single tower jaggedly shattered, a few other tiny touches, the artist had given it an atmosphere of almost unbearable desolation. It was the same fabulous metropolis--but it was tragic, deserted, lost. Peering hopelessly from the summit of the broken tower was a tiny face, looking directly upward at Andreson. He allowed himself an appreciative shudder, and methodically went around the gallery, following the history the pictures built up. It seemed commonplace enough: a race of space-travellers who had colonized the Earth, perhaps some time in the dim past, had built a civilization, and had finally succumbed to some undepicted doom. What was amazing was the utterly convincing way the well-worn story was told. It was real--super-real, indeed, for it commanded more belief and sympathy than the everyday human tragedies. Andreson took out his fountain pen and an unopened letter and walked toward the door. He must get the address of this place and attempt to locate the artist. John Kimball's inscription on the envelope reminded him that Johnny, though a scientist, dabbled in the arts and would be interested. He ripped open the flap, then stopped in mid-stride, ducked under the rayon cord to look at the spaceship scene. In many ways this was the most wonderful of the lot. Even a night sky or a telescope field has no depth; it is merely a black surface containing spots of light; but the picture surpassed nature. It had a stereoscopic quality, all the more startling because it was impossible to ascertain how it was done. Andreson noted with a chuckle that the agent had placed the paintings in such order that there was a strong draft blowing toward the picture, as if being drained away into that awesome vacuum. A strictly phony trick, but clever nonetheless. Curious in spite of his better instincts, he put out a tentative finger to the surface of the scene-- The fountain pen clattered to the floor. He gaped idiotically, and stirred with his finger at the nothingness where the picture still seemed to be. In his shock-numbed mind two words burned fiercely: _It's real._ Ridiculous. Tensely he forced himself to move his hand in deeper, against the yelling of his nerves. It struck a slight, tingling resistance, like a curtain of static electricity--and then the blood was pounding in each finger as if trying to burst through the skin. He snatched the hand back. There _was_ a vacuum there; cut off from the room by some unseen force through which the air was leaking rapidly.