e dark screen came to life to show a
clear-cut picture of a man who sat at a telescope; whose hand held a
radiophone; and who glanced up frowningly and said: "Yes, this is Doctor
Roche."

Chet's response was immediate.

"Bullard speaking; Chet Bullard, at New York. When I was in your
observatory yesterday, Doctor, you said that you had seen flashes of
light on the Moon. You remember that, don't you? You saw them some
months ago while I was on the Dark Moon."

* * * * *

The man in that distant observatory was no longer scowling at this
interruption of his work. His smile was echoed by the cordial tone of
his voice that rang clearly through the great hall.

"Correct, Mr. Bullard. An observer at our two hundred-inch reflector
reported them on two successive nights. They were inside the crater of
Hercules."

From his place at the center of the stage the waiting Commander of Air
protested:

"Come--come! We know all about that, Bullard. Are you trying to say--"

The voice of the astronomer was speaking again:

"You will no doubt be interested to know that the lights occurred again
yesterday at about this time.... Let me see if they are on now. I will
have the two hundred-inch instrument used as before, and will show you
what we see.

"Watch your screen, but don't expect to find any substantiation of your
wild theory that these lights have a human origin." He laughed softly.
"No atmosphere to speak of there, you know; we have determined that very
definitely."

On the screen the picture of the smiling man flashed off; it was
replaced by an unflickering darkness that came abruptly into softly
shaded light. There was an expanse of volcanic terrain and a round
orifice of tremendous size, where the sunlight cast black shadows. Other
shaded portions about were like rocky, broken ground.

* * * * *

To Chet, staring at the strange conformation, came the quick sense of
hanging above that ground and looking down upon it. And he knew that in
New York he was looking through a great telescope down under the world
and was staring straight down into the throat of an extinct volcano on
the Moon.

There were few wonders of the modern world that could thrill the master
pilot with any feeling of amazement, but here was a new experience. He
would have spoken, would have ejaculated some word of wonder, but for
the new light that claimed his eyes and brain.

The vo