-"

"Cave bears?"

Ashe sighed with weary patience. "Get it through your head, Murdock,
that history is much longer than you seem to think. Cave bears and the
use of bronze weapons do not overlap. No, you will have to go back maybe
several thousand years earlier and then hunt your bear with a
flint-tipped spear in your hand if you are fool enough to try it."

"Or take a rifle with you." Ross made a suggestion he had longed to
voice for some time.

Ashe rounded on him swiftly, and Ross knew him well enough now to
realize that he was seriously displeased.

"That is just what you don't do, Murdock, not from this base, as you
well know by now. You take no weapon from here which is not designed for
the period in which your run lies. Just as you do not become embroiled
while on that run in any action which might influence the course of
history."

Ross went on polishing the blade he held. "What would happen if someone
did break that rule?"

Ashe put down the dagger he had been playing with. "We don't know--we
just don't know. So far we have operated in the fringe territory,
keeping away from any district with a history which we can trace
accurately. Maybe some day--" his eyes were on a wall of weapon racks he
plainly did not see--"maybe some day we can stand and watch the rise of
the pyramids, witness the march of Alexander's armies.... But not yet.
We stay away from history, and we are sure that the Reds are doing the
same. It has become the old problem once presented by the atom bomb.
Nobody wants to upset the balance and take the consequences. Let us find
their outpost and we'll withdraw our men from all the other runs at
once."

"What makes everyone so sure that they have an outpost somewhere?
Couldn't they be working right at the main source, sir?"

"They could, but for some reason they are not. As for how we know that
much, it's information received." Ashe smiled thinly. "No, the source is
much farther back in time than their halfway post. But if we find that,
then we can trail them. So we plant men in suitable eras and hope for
the best. That's a good weapon you have there, Murdock. Are you willing
to wear it in earnest?"

The inflection in that question caught Ross's full attention. His gray
eyes met those blue ones. This was it--at long last.

"Right away?"

Ashe picked up a belt of bronze plates strung together with chains, a
twin to that Ross had seen worn by the wolf slayer. He held it out to
the y