guesses
could be made, and they were made; but nobody outside the closed-in area
save a very few top-ranking officials had any real knowledge. The world
only knew that something drastic and remarkable was in prospect.

Mike, though, was able to write a letter to the girl who'd written him.
Major Holt arranged it. Mike wrote his letter on paper supplied by
Security, with ink supplied by Security, and while watched by Security
officers. His letter was censored by Major Holt himself, and it did not
reveal that Mike was back on Earth. But it did invite a reply--and Mike
sweated as he waited for one.

The others had plenty to sweat about. Joe and Haney and the Chief were
acting as instructors to the Moonship's crew. They taught practical
space navigation. At first they thought they hadn't much to pass on, but
they found out otherwise. They had to pass on data on everything from
how to walk to how to drink coffee, how to eat, sleep, why one should
wear gravity harness, and the manners and customs of ships in space.
They had to show why in space fighting a ship might send missiles on
before it, but would really expect to do damage with those it left
behind. They had to warn of the dangers of unshielded sunshine, and the
equal danger of standing in shadow for more than five minutes, and----

They had material for six months of instruction courses, but there was
barely a week to pass it on. Joe was run ragged, but in spite of
everything he managed to talk at some length with Sally. He found
himself curiously anxious to discuss any number of things with his
father, too, who suddenly appeared to be much more intelligent than Joe
had ever noticed before.

He was almost unhappy when it was certain that the Moonship would take
off for space on the following day. He talked about it with Sally the
night before take-off.

"Look," he said awkwardly. "As far as I'm concerned this has turned out
a pretty sickly business. But when we have got a base on the Moon, it'll
be a good job done. There will be one thing that nobody can stop!
Everybody's been living in terror of war. If we hold the Moon the cold
war will be ended. You can't kick on my wanting to help end that!"

Sally smiled at him in the moonlight.

"And--meanwhile," said Joe clumsily, "well--when I come back we can do
some serious talking about--well--careers and such things. Until
then--no use. Right?"

Sally's smile wavered. "Very sensible," she agreed wrily. "And awful