the earth below El Viejo,
working against time to intercept the rising magma.

Scientists had arrived, too, and they were taking over much of the
detail of keeping track of the magma. Each scientist had his own special
field of interest, but all were anxious to have the data from tracings.
There were geophysicists, including volcanologists and seismologists;
mineralogists and more geologists.

"Nothing much left for us to do," Rick said, a little sadly.

"Except watch," Scotty corrected. "That's enough! Great crumbling
craters, what do you want? A mystery every day?"

Rick had to grin. "I guess this is enough. But one thing I want to do is
go over to the volcanic pipe and see how Guevara and Connel are making
out."

"You will have an escort," a voice said from behind them. They turned to
greet Ricardo Montoya. "Now that we can turn our attention to that pair,
I think we should have a talk with them. To make the talk easier, we
will put bars between us."

"You're going to arrest them?" Rick asked.

"Of course! What did you think?"

"Right now?"

"If you want to come along, join me. Now is as good a time as any. If we
can find them, of course."

The boys joined Montoya in the front seat of a military vehicle. The
back was loaded with his men. Montoya at once steered for the trail to
the volcanic pipe. It was only a thousand yards to the north from the
point selected for the big hole. Even around the site of the hole there
were diamond seekers, and it was hard to find a piece of ground that had
not been tried with a shovel.

As they got closer to the diamond field the numbers of treasure hunters
increased until, as Scotty remarked, they were thicker than fleas at a
mutt show. Montoya had to lean on the horn continually, and even then
the San Luzians paid little attention.

Finally the group got out and walked. It was easier to move on foot
through the frantically digging mob. Strangely, there was little noise.
Each individual seemed intent on his own little hole. But the digging
was futile. There was no yellow ground under the flying shovels.

Then the group did reach yellow ground, and met rifles in the hands of
Guevara's peons. Evidently Guevara had put a ring of men around the
volcanic pipe and planned to hold it by force of arms.

Rick looked at Montoya. What would he do now?

The young officer looked haughtily at the nearest peons and demanded in
Spanish, "Do you know me?"

One of them nodded resp