oor quietly, he seized the fellow before he could move
his hand to his wrist. Thwarted in his attempt to vanish from sight,
the diminutive guard attempted an outcry. But Kendrick promptly
throttled him.

* * * * *

Marjorie had reappeared by now and together they bound him to a chair
with a gilded cord torn from the drapery.

Removing the precious mechanism from his wrist, Kendrick slipped it on
his own.

"Now let's go!" he said, pressing the protruding square button of the
device. "We haven't a minute to--my golly, what a peculiar sensation!"

"It is rather odd, isn't it?" she laughed, pressing her own and
joining him in that invisible realm.

"Feels like a combination electric massage and cold shower! Where are
you, anyway? I can't see you."

"Of course you can't!" came an unseen tinkle. "Here!"

He felt her brush him.

"Better hold hands," he suggested, then gave an invisible flush he was
glad she couldn't see.

"All right. A good idea."

Her delicate hand came into his, soft, warm. Heart vibrating even
faster than his body, his whole being a-quiver with a strange
exaltation, Kendrick opened the door, and they left the apartment.

* * * * *

The next half-hour was the tensest either of then had ever
experienced. Every foot of the way was fraught with peril.

Not only did they have to carefully avoid the visible swarms of little
people who hurried everywhere, but had to be on their guard as well
against any who might be moving about like themselves under cover of
invisibility.

Nor could they use any elevator or public conveyances, but were
obliged to make their way down to the concourse by heaven knew how
many flights of stairs, and cross heaven knew how many teeming streets
on foot, before they reached the amber court, below which the
trap-door and their hope of freedom.

They got there at last, however, descended, and peered down from that
yawning brink upon the desert floor--to draw back with gasps of
dismay. For the area still gleamed semi-molten from the stupendous
blast that had wiped out Kendrick's camp.

"W-what is it?" she gasped.

Swiftly he told her.

"But isn't there any way around it? Look, over there to the left. One
edge of the crater seems to end almost underneath us."

It was true that the center of the caldron was far to the right of
where they stood, and that its left rim was only a little within their
direct