n, definitely coming out of the Tube,
there was a hollow, booming noise.

* * * * *

It had been echoed and re-echoed amid the twistings of the Tube, but
only an animal could have made it. It grew louder, a monstrous roar.
Then yells sounded suddenly above it--human yells, wild yells, insane,
half-gibbering yells of hysterical excitement and blood lust. The
beast-thing bellowed and an ululating chorus of joyous screams arose.
The laboratory reverberated with the thunderous noise. Then there was
the sound of crashing and of paddings, and abruptly the noise was
diminishing as if its source were moving farther away. The beast-thing
roared and bellowed as if in agony, and the yelling noise seemed to
show that men were following close upon its flanks.

Those in the laboratory seemed to awaken as if from a bad dream.
Denham was kneeling before the mouth of the Tube, an automatic rifle
in his hands. Tommy Reames stood grimly before Evelyn. He'd snatched
up a pair of automatic pistols. Smithers clutched a spanner and
watched the mouth of the Tube with a strained attention. Evelyn stood
shivering behind Tommy.

Tommy said with a hint of grim humor:

"I don't think there's any doubt about the Tube having gotten through.
That's the Fifth Dimension planet, all right."

He smiled at Evelyn. She was deathly pale.

"I--remember--hearing noises like that...."

Denham stood up. He painstakingly slipped on the safety of his rifle
and laid it on a bench with the other guns. There was a small arsenal
on a bench at one side of the laboratory. The array looked much more
like arms for in expedition into dangerous territory than a normal
part of apparatus for an experiment in rather abstruse mathematical
physics. There were even gas masks on the bench, and some of those
converted brass Very pistols now used only for discharging tear- and
sternutatory-gas bombs.

"The Tube wasn't seen, anyhow," said Professor Denham briskly. "Who's
going through first?"

Tommy slung a cartridge belt about his waist and a gas mask about his
neck.

"I am," he said shortly. "We'll want to camouflage the mouth of the
Tube. I'll watch a bit before I get out."

He crawled into the mouth of the twisted pipe.

* * * * *

The Tube was nearly three feet across, each section was five feet
long, and there were gigantic solenoids at each end of each section.

It was not an experiment made at r