ruin
you; seize your ship; steal for himself the glory of your invention.
Would you go back and deliver yourself into his hands--because of me?"

The brown eyes, Harkness found, were upon his with an expression he
could not fathom.

"Yes," he said simply.

And still the eyes looked into his. There was laughter in them, and
something else whose meaning was concealed.

"I ask you not to do this," she was saying. "You will succeed; I read
it in your face. Let me go with you; let me share in the adventure. I
am begging this of you. It is your turn to be generous."

Harkness' hand upon the metal ball held it motionless within its
enclosing cage. From astern there came to him the muffled roar of a
blast that drove them on and out into space--black, velvety space,
thick-studded with sharp points of light.... He stared into that
wondrous night, then back into the eyes that looked steadily,
unfathomably, into his.... And his hand was unresisting as the
strong, slender fingers about his wrist drew it back....

They were off for the Dark Moon: their journey, truly, was begun. And
this girl, whom he had told himself to forget, was going with them.
There was much that he did not understand, but he knew that he was
glad with a gladness that transcended all previous thrills of the
perilous plan.

CHAPTER V

_The "Dark Moon"_

They were seated in the cabin of the man-made meteor that the brain of
Harkness had conceived--two men and a girl. And they stared at one
another unsmilingly, with eyes which reflected their comprehension of
the risks that they ran and the dangers which lay ahead in the dark
void. Yet the brown eyes of Mam'selle Diane, no less than the others,
were afire with the thrill of adventure--the same response to the same
lure that has carried men to each new exploration--or to their death.

Behind them, a rear lookout port framed a picture of awful majesty.
The earth was a great disc, faintly luminous in a curtain of dead
black. From beyond it, a hidden sun made glorious flame of the disc's
entire rim. And, streaming toward it, a straight, blasting line from
their stern exhaust, was an arrow of blue.

It had taken form slowly, that arrow of blue fire, and Harkness
answered an unspoken question from the girl.

"Hydrogen and oxygen," he explained. "It is an explosive mixture at
this height, but too thin to take fire. It will pass. Beyond this is
pure hydrogen. And then, nothing."

He turned to switch o