l." Rick took the opportunity to tell Farid of the incident at
the museum that morning. He described briefly how they had been
followed, then attacked on the museum path.

Farid frowned. "I'm sorry to hear it. Cairo is pretty law-abiding,
compared to what it used to be. But we still have crime, just as you do
in your big cities. You didn't lose your wallets or anything valuable?"

"Nothing. We think they were after the cat."

"They didn't get it?"

"No. I didn't have it on me."

"That was fortunate." Farid frowned. "But why would anyone want the
cat?"

Rick did not have an answer for that, and said so. The scientist smiled.
"A cat isn't exactly big game for thieves, is it? On the other hand, the
museum itself was robbed several weeks ago in spite of the guards.
Thieves got away with a necklace supposed to have belonged to Kefren,
who built the middle pyramid over there."

"Was it valuable?" Scotty asked.

"More than valuable. It is irreplaceable. In terms of cash, however, the
value is around a quarter of a million dollars."

Rick whistled. "No wonder the guards watched us this morning."

Dr. Kerama called, "Hakim, can you help with these tracings, please?"

Farid joined the other scientists, leaving the boys to their own
devices. Rick hunted until he found a space under an amplifier that was
big enough for the two extra kittens. The space was covered by an access
door. The kittens would be safe there. It would be no real loss if they
were stolen, anyway.

Later, the boys helped check circuits while the radio telescope swung
through a variety of arcs, with Farid at the controls. The strange
signal came while the telescope was pointing only in one direction.

Rick asked Winston, "Could it really be coming from a single source in
outer space?"

Winston shrugged. "We've thought of that. If the source remained fixed,
we'd accept it as the most logical explanation. But since Kerama and
Farid first noticed the signal it has shifted its apparent location by
many degrees. That's why we think it must have some local explanation."

Rick understood. The sources in space studied by the radio telescopes
were fixed, in the same sense that the stars themselves were fixed. Of
course everything in the galaxy--even in the universe--was in motion,
but in spite of the enormous velocities, the change in location would
not be particularly apparent in a short time, or even in a lifetime.

A short distance away was a wonderf