ices, laboratories: it was a
place of busy men. And Professor Sykes, he found, was busy. But he
spared a few minutes to answer courteously the questions of this slim
young fellow in the khaki uniform of the air service.

"What can I do for you?" asked Professor Sykes.

"No dreamer, this man," thought McGuire as he looked at the short,
stocky figure of the scientist. Clear eyes glanced sharply from under
shaggy brows; there were papers in his hand scrawled over with strange
mathematical symbols.

"You can answer some fool questions," said Lieutenant McGuire
abruptly, "if you don't mind."

The scientist smiled broadly. "We're used to that," he told the young
officer; "you can't think of any worse ones than those we have heard.
Have a chair."

McGuire drew a clipping from his pocket--it was the newspaper account
he had read--and he handed it to Professor Sykes.

"I came to see you about this," he began.

The lips of Professor Sykes lost their genial curve; they straightened
to a hard line. "Nothing for publication," he said curtly. "As usual
they enlarged upon the report and made assumptions and inferences not
warranted by facts."

"But you did see that flash?"

"By visual observation I saw a bright area formed on the
terminator--yes! We have no photographic corroboration."

"I am wondering what it meant."

"That is your privilege--and mine," said the scientist coldly.

"But it said there," McGuire persisted, "that it might have been a
signal of some sort."

"_I_ did not say so: that is an inference only. I have told you,
Lieutenant"--he glanced at the card in his hand--"--Lieutenant
McGuire--all that I know. We deal in facts up here, and we leave the
brilliant theorizing to the journalists."

* * * * *

The young officer felt distinctly disconcerted. He did not know
exactly what he had expected from this man--what corroboration of his
wild surmises--but he was getting nowhere, he admitted. And he
resented the cold aloofness of the scientist before him.

"I am not trying to pin you down on anything," he said, and his tone
carried a hint of the nervous strain that had been his. "I am trying
to learn something."

"Just what?" the other inquired.

"Could that flash have been a signal?"

"You may think so if you wish: I have told you all that I know. And
now," he added, and rose from his chair, "I must ask to be excused; I
have work to do."

McGuire came slowly to his