e he had managed to come this far without the aid of any
guide markers.

As the darkening shadows of night began to spread over the jungle the
young cadet began to worry. He had been allowed thirty-six hours to make
it back to the _Polaris_, communicate with Commander Walters, and tell
him the position of the base, and Tom had to allow time for the Solar
Guard fleet to assemble and blast off, so that it would arrive at the
base at exactly noon on the next day. He had to reach the Sinclair
plantation before nightfall or the fleet would never make it.

Suddenly to his left he heard a noisy crashing of underbrush and the
roar of a large beast. Tom hesitated. He could hide; he could fight; or
he could break to his right and try to escape. The beast growled
menacingly. It had picked up his scent. Tom was sure it was a large
beast on the prowl for food, and he decided that he could not waste time
hiding, or risk being injured in a battle with the jungle prowler. He
quickly broke to his right and raced through the jungle. Behind him, the
beast picked up the chase, the ground trembling with its approach. It
began to gain on him. Tom was suddenly conscious of having lost his
bearings. He might be running away from the clearing!

Still he ran on, legs aching and lungs burning. He charged through the
underbrush that threatened any moment to trip him. When he was almost at
the point of complete exhaustion, and ready to turn and face the beast
behind him, he saw something that renewed his spirit and sent new
strength through his body. Ahead through the vines and creepers, the
slender nose of the _Polaris_ was outlined against the twilight sky.

Disregarding the beast behind him, he plunged through the last few feet
of jungle undergrowth and raced into the clearing around the Sinclair
home. Behind him, the beast suddenly stopped growling, and when Tom
reached the air lock of the _Polaris_, he saw that the beast had turned
back, reluctant to come out of the protection of the jungle.

Tom pulled the air-lock port open and was about to step inside when he
heard a harsh voice coming from the shadow of the port stabilizer.

"Just stop right where you are!"

Tom jerked around. Rex Sinclair stepped out of the shadow, a paralo-ray
gun in his hand.

"Mr. Sinclair!" cried Tom, suddenly relieved. "Boy, am I glad to see
you!" He jumped to the ground. "Don't you recognize me? Cadet Corbett!"

[Illustration: _"Mr. Sinclair!" cried Tom, su