s."

"Relax," she suggested. "You've done all you can."

"I guess it's back to your gilded cage for you, baby," he said. "My
money didn't last."

"Sometimes you behave like a mad dog," she observed. "I'm not sure I
like you. You enjoyed that butchery out there. You hated to come
inside. What did it prove? There are too many of them. They'll kill
us, eventually. Or starve us out. Have you any bright ideas?"

Denver was silent. None of his ideas were very bright. He was at the
end of his rope. He had tied a knot in it and hung on. But the rope
seemed very short and very insecure.

"Hang on, I guess. Just hang on and wait. They may try a rush. If they
do I'll bathe the entrance in a full load from my blaster. If they
don't rush, we sit it out. Sit and wait for a miracle. It won't happen
but we can hope."

Darbor tried to hug the darkness around her. She was a Martian,
tough-minded she hoped. It would be nasty, either way. But death was
not pleasant. She must try to be strong and face whatever came. She
shrugged and resigned herself.

"When the time comes I'll try to think of something touching and
significant to say," she promised.

"You hold the fort," Denver told her. "And don't hesitate to shoot if
you have to. There's a chance to wipe them out if they try to force in
all at once. They won't, but--"

"Where are you going? For a walk?"

"Have to see a man about a dog. There may be a back entrance. I doubt
it, since Martian workings on the Moon were never very deep. But I'd
like a look at the jackpot. Do you mind?"

Darbor sighed. "Not if you hurry back."

Deep inside the long gallery was a huge, vaulted chamber. Here, Denver
found what he sought. There was no back entrance. The mine was a trap
that had closed on him and Darbor.

Old Martian workings, yes. But whatever the Martians had sought and
delved from the mooncrust was gone. Layered veins had petered out,
were exhausted, empty. Some glittering, crystalline smears remained in
the crevices but the crystals were dull and life-less. Denver bent
close, sensed familiarity. The substance was not unknown. He wetted a
finger and probed with it, rubbed again and tested for taste.

The taste was sharp and bitter. As bitter as his disappointment. It
was all a grim joke. Valuable enough once to be used as money in the
old days on earth. But hardly valuable enough, then, even in real
quantity, to be worth the six lives it had cost up to now--counting
his and D