Even such fugitive grasping at Logical straws vanished when he saw the immense squat mass of Giac, rising like a steel-and-concrete toad from the wastes of the California desert. It seemed absurd even to think that such an imposing and complex structure should have been reared on the mathematics of the immortal author of Alice in Wonderland, Through the Looking Glass and The Hunting of the Snark.

For Giac was imposing, even to a man biased against computers from birth. Nor did du Fresne's smugness help Lindsay's assurance a bit. He explained how each of the block-large preliminary feeders worked—one for mathematical symbols, one for oral recording, a third for written exposition. Each worked simultaneously and in three different ways—via drum-memory banks, via punched tapes, via the new "ear-tubes" that responded to sound.

Then there were the preliminary synthesizers, each of which unified in vapor-plutonium tubes the findings of its three separate feeders. Next, a towering black-metal giant filling three walls of a cubical room twenty metres in each dimension, came the final synthesizer, which coordinated the findings of the preliminary synthesizers and fed them into Giac itself.

The master machine was the least imposing of all. It stood like an alabaster stele in the center of an immense chamber arranged like a theater-in-the-round. But du Fresne, peering through his strawberry spectacles, said gloatingly, "Don't be deceived by the size, ladies and gentlemen. All but what you see of Giac is underground. It is contained in an all-metal cell one million cubic metres in volume. And it is infallible."

Fortunately Lindsay was given a half hour of final preparation in one of the small offices with which the above-ground building was honeycombed. Nina came with him—by request.

"I can't do it," he told her abruptly.

"Don't worry, darling, you'll think of something," she said. She tried to embrace him but he was too worried to respond. After awhile she said, "Why not put a direct question. Ask it if it's infallible."

"It could hardly tell a lie on itself," he replied.

"What if such a question involved destruction of part of itself in the answer?" she asked.

"It might—though I presume du Fresne and his boys have prepared it for such jokers. And anyway, what sort of question would do that? Got any ideas?"