the girls circled to one side.

"Where are we going?" Mercer asked.

"A trail--near us somewhere. A trail to the Lone City. There we land."

Mercer saw the trail in a moment. It came out of the woods and struck the
shore by a little bight where boats could land. The girls swooped
downward, and in a moment more the platform was lying motionless on the
beach.

Mercer looked around. It was light enough to see objects in the immediate
foreground--a gray twilight. The forest came almost to the water's edge.
He saw now the trees might have been firs, but with small, twisted trunks,
few branches except near the top, and very few leaves. They seemed somehow
very naked and starved--indeed, it surprised him that they could grow at
all in such a rocky waste. The end of the trail was close before him. It
appeared merely an opening in the trees with the fallen logs and
underbrush cleared away.

The girls were obviously cold, standing idle now after their long flight.
Mercer lost no time in preparing for the return journey. He tumbled his
captives unceremoniously off the platform and set the box of food and
blankets beside them.

"What's this, Anina?"

He was holding in his palm a tiny metal cylinder.

Anina took it from him.

"For fire, see?"

She picked up a bit of driftwood, and, holding the end of the cylinder
against it, pressed a little button. A curl of smoke rose from the wood,
and in a moment a wisp of flame.

"A light-ray!" Mercer exclaimed.

"The ray--but different."

She tossed the blazing bit of wood aside, and held her hand a foot or so
in front of the cylinder.

"No danger! See?" She brought her hand closer. "Heat here--close--no heat
far away."

Mercer understood then that this was not a light-ray projector, but a
method of producing heat with the property of radiation, but not of
projection--a different and harmless form of the ray.

He took the little cylinder from the girl, inspected it curiously, then
laid it on the blankets.

"They'll need it, I guess, if it's any colder where they're going."

He set one of the captives free.

"Anina, tell him to sit quiet until we've gone. Then he can cut the others
loose." He tossed a knife into the box. "Come on, Anina; let's get away."

They were about ready to start back, when Mercer suddenly decided he was
hungry. He hopped off the platform. "They don't need all that food."

He gathered some of the little flat cakes of dough in his hands. "Want