e replied brightly. But her brightness
became a bit strained as the day wore on. The trip, for Lindsay, was
sheer nightmare. _No sane man can wag his tail_, he kept thinking.

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 i