oan retorted
calmly, "and as long as we recalled them within the twelve-hour
limit they always came back alive and unhurt. There's no reason why
a human being should not be able to make the round trip just as
safely. Ever since our Silver Belts first came back with the weird
plant and mineral fragments which proved that there really is such a
place as Arret, I've been wild to see with my own eyes the
incredible things that must exist there."

Joan waved her hand in gay farewell. "Good-by, Uncle Ben and Larry!
I know that you'll drag me back just as quickly as you can possibly
dash over to the recall switch, but I'll at least have had a few
precious seconds of sightseeing as Earth's first human visitor to
Arret!"

* * * * *

Larry Powell was already sprinting for the mechanism as Joan jerked
the cord that ran to the switch, but he was barely half-way across
the intervening space when the big atomic projector flared forth in
a brilliant gush of roseate flame.

For a fraction of a second Joan's slender figure was outlined in the
very heart of the ruddy glow, then vanished completely. There was
left only a short length of the switch cord to indicate that the
girl had ever stood there.

Powell reached the mechanism and shut off the projector's flame,
then turned swiftly to the control-panel of the recall mechanism. As
he closed the switch on this panel, three banks of tubes set in
triangular form around the floor-plate upon which Joan had stood
glowed a brilliant and blinding green.

Shielding his eyes from the glare with an upraised forearm, Powell
began stepping a rheostat up to more and more power. In his anxiety,
he increased the power far too quickly. There was a sudden gush of
blue-white flame from the heart of the mechanism, together with the
hissing crackle of fusing metal. The green light in the tubes
promptly died.

Benjamin Marlowe was bending over the apparatus almost instantly. A
moment later he raised a face that had suddenly gone white. There
was terror in his eyes as he turned to his assistant.

"The entire second series of coils is burned out, Larry!" he gasped
in consternation. "Joan is marooned over there in Arret--marooned in
that grim unknown land as completely beyond our reach as though she
were upon one of the moons of Mars!"

For a long moment the two men gazed at each other with
horror-stricken faces, dazed and shaken. Then they quickly drew
themselves tog