owly a somber twilight began to fall, and Axelson rose.

"Let us walk in the gardens during the reign of Erebos," he said.

"Erebos?" asked Nat.

"The black world that overshadows us each sleeping period," answered
Axelson.

Nat knew what he meant. The dark companion of Eros revolves around it
every six hours; the day of Eros would therefore never be longer than
six hours, this without reckoning the revolution of Eros around the
sun. But owing to its small size, it was probable that it was bathed
in almost perpetual sunshine.

The sweet scent of the flowers, much stronger than of any flowers on
earth, filled the air. They walked across the green lawn and entered a
jungle path, with bamboos and creeping plants on either side, and huge
palmlike trees. Behind them stalked the guards with their ray-rods.

A lake of deepest black disclosed itself. Suddenly Madge uttered a
scream and clung to Nat. "Look, look!" she cried. "It's horrible!"

* * * * *

Suddenly Nat realized that the lake swarmed with monsters. They were
of crocodilian form, but twice the size of the largest crocodile, and
sprawled over one another in the shallows beside the margin. As the
party drew near, an enormous monster began waddling on its clawed feet
toward them.

A mouth half the length of the creature opened, disclosing a purplish
tongue and hideous fangs. Madge screamed again.

"Ah, so fear exists on Earth, too?" asked Axelson blandly. "That makes
my conquest sure. I suspected it, and yet I was not sure that science
had not conquered it. But there is no cause for fear. A magnetic field
protects us. See!"

For the waddling monster suddenly stopped short as if brought up
sharply by the bars of a cage, and drew back.

Axelson turned and wheezed in the Moon language--if the gibbering of
the dwarfs could be called speech--and one of the guards answered him.

"These primitive dwellers on Eros I have preserved," said Axelson, "as
a means of discipline. The Moon animals are afraid of them. I keep a
supply of those who have transgressed my laws to feed them. See!"

He turned and pointed. Two guards were bringing a gibbering,
screeching, struggling Moon man with them. Despite his strength, he
seemed incapable of making any resistance, but his whole body
quivered, and his hideous face was contorted with agony of terror.

At a distance of some fifty feet they turned aside into a little
bypath through the jungle, r