lass, the engineers call it. Each one has been slightly different
than the one before, of course, as they ironed out the bugs in their
operation. But each one has been a failure. Not one of them would pass
the test for space-worthiness."

"Not a failure of the drive or the ordinary mechanisms of the ship, I
take it?"

Ravenhurst sniffed. "Of course not. The brain. The ships became, as
you might say, _non compos mentis_. As a matter of fact, when the last
one simply tried to burrow into the surface of Eros by reversing its
drive, one of the roboticists said that a coroner's jury would have
returned a verdict of 'suicide while of unsound mind' if there were
inquests held for spaceships."

"That doesn't make much sense," I said.

"No. It doesn't. It isn't sensible. Those ships' brains shouldn't have
behaved that way. Robot brains don't go mad unless they're given
instructions to do so--conflicting orders, erroneous information, that
sort of thing. Or, unless they have actual physical defects in the
brains themselves."

"The brains can handle the job of flying a ship all right, though?" I
asked. "I mean, they have the capacity for it?"

"Certainly. They're the same type that's used to control the
automobile traffic on the Eastern Seaboard Highway Network of North
America. If they can control the movement of millions of cars, there's
no reason why they can't control a spaceship."

"No," I said, "I suppose not." I thought it over for a second, then
asked, "But what do your robotics men say is causing the
malfunctions?"

"That's where the problem comes in, Mr. Oak." He pursed his pudgy
lips, and his eyes narrowed. "The opinions are divided. Some of the
men say it's simply a case of engineering failure--that the bugs
haven't been worked out of this new combination, but that as soon as
they are, everything will work as smoothly as butter. Others say that
only deliberate tampering could cause those failures. And still others
say that there's not enough evidence to prove either of those theories
is correct."

"But your opinion is that it's sabotage?"

"Exactly," said Ravenhurst, "and I know who is doing it and why."

I didn't try to conceal the little bit of surprise that gave me. "You
know the man who's responsible?"

He shook his head rapidly, making his jowls wobble. "I didn't mean
that. It's not a single man; it's a group."

"Maybe you'd better go into a little more detail on that, Mr.
Ravenhurst."

He nodd