we left the _Planetara_ for Halsey's office. It was
not a long trip. We went on the upper monorail, descending into the
subterranean city at Park Circle 30.

We had never been to Halsey's office before. Now we found it to be a
gloomy, vaultlike place in one of the deepest corridors. The door
lifted.

"Gregg Haljan and Daniel Dean."

The guard stood aside. "Come in."

I own that my heart was unduly thumping as we entered. The door
dropped behind us. It was a small blue-lit apartment--a steel-lined
room like a vault.

Colonel Halsey sat at his desk. And the big, heavy-set, florid Captain
Carter--our commander on the _Planetara_--was here. That surprised us:
we had not seen him leave the ship.

Halsey smiled at us gravely. Captain Carter spoke with an ominous
calmness: "Sit down, lads."

We took the seats. There was an alarming solemnity about this. If I
had been guilty of anything that I could think of, it would have been
frightening. But Halsey's words reassured me.

"It's about the Grantline Moon Expedition. In spite of our secrecy,
the news has gotten out. We want to know how. Can you tell us?"

Captain Carter's huge bulk--he was about as tall as I am--towered over
us as we sat before Halsey's desk. "If you lads have told anyone--said
anything--let _slip_ the slightest hint about it...."

Snap smiled with relief; but he turned solemn at once. "I haven't. Not
a word!"

"Nor have I!" I declared.

The Grantline Moon Expedition! We had not thought of that as a reason
for this summons. Johnny Grantline was a close friend of ours. He had
organized an exploring expedition to the Moon. Uninhabited, with its
bleak, forbidding, airless, waterless surface, the Moon--even though
so close to the Earth--was seldom visited. No regular ship ever
stopped there. A few exploring parties of recent years had come to
grief.

But there was a persistent rumor that upon the Moon, mineral riches of
fabulous wealth were awaiting discovery. The thing had already caused
some interplanetary complications. The aggressive Martians would be
only too glad to explore the Moon. But the United States of the World,
which came into being in 2067, definitely warned them away. The Moon
was Earth territory, we announced, and we would protect it as such.

There was, nevertheless, a realization by our government, that
whatever riches might be upon the Moon should be seized at once and
held by some reputable Earth Company. And when John Grantl