d the time-tape. Each hour and
minute was there; each movement of the controls was indicated; each
trifling variation in the power of the generator's blast. Chet made some
careful computations and passed the paper to Harkness, who tilted the
time-tape recorder that he might see the record.

"Check this, will you, Walt?" Chet was asking. "It is based on the time
of our other trip, acceleration assumed as one thousand miles per hour
per hour out of air--"

The scientist interrupted; he spoke in English that was carefully
precise.

"It should lie directly ahead--the Dark Moon. I have calculated with
exactness."

Walter Harkness had snatched up a pair of binoculars. He swung sharply
from lookout to lookout while he searched the heavens.

"It's damned lucky for us that you made a slight error," Chet was
telling the other.

"Error?" Kreiss challenged. "Impossible!"

"Then you and I are dead right this minute," Chet told him. "We are
crossing the orbit of the Dark Moon--crossing at twenty thousand miles
per hour relative to Earth, slightly in excess of that figure relative
to the Dark Moon. If it had been here--!" He had been watching Harkness
anxiously; he bit off his words as the binoculars were thrust into his
hand.

"There she comes," Harkness told him quietly; "it's up to you!"

But Chet did not need the glasses. With his unaided eyes he could see a
faint circle of violet light. It lay ahead and slightly above, and it
grew visibly larger as he watched. A ring of nothingness, whose outline
was the faintest shimmering halo; more of the distant stars winked out
swiftly behind that ghostly circle; it was the Dark Moon!--and it was
rushing upon them!

* * * * *

Chet swung an instrument upon it. He picked out a jet of violet light
that could be distinguished, and he followed it with the cross-hairs
while he twirled a micrometer screw; then he swiftly copied the reading
that the instrument had inscribed. The invisible disk with its ghostly
edges of violet was perceptibly larger as he slammed over the
control-ball to up-end them in air.

Under the control-room's nitron illuminator the cheeks of Herr Doktor
Kreiss were pale and bloodless as if his heart had ceased to function.
Harkness had moved quietly back to the side of Diane Delacouer and was
holding her two hands firmly in his.

The very air seemed charged with the quick tenseness of emotions.
Schwartzmann must have sensed it