the end of the room and bade
them enter it. The vibrant light caressed their limbs.

"When I close this door," he said, "you will find yourselves back in
the tunnel. Board one of the submarine-cars on the siding and proceed
to the wreck." He gave them detailed instructions how to operate the
car. "Then get your weapons and return. Do you understand?"

They nodded.

"The workers possess no arms the equal of machine-guns and bombs. They
will be at your mercy. Remember that you are fighting for our lives
and that, if you save them, your reward will be great. Fear nothing."

The door closed. After a moment there was a blinding flash, a moment
of swooning darkness, and then they were staring through transparent
walls into the phosphorescent gloom of the underseas crypt. Suddenly,
what they had recently undergone seemed the product of an illusion, a
dream. Ward shook himself vigorously. "I guess it was real enough," he
said. "Let us see if the car works."

They ran out to the wreck and returned without trouble. The
machine-gun was mounted for action and the gas-bombs slung over their
shoulders in convenient bags. "All right," said Miles tensely, "let us
go."

Again they entered the crystal chamber; again there was the flash of
light and the sensation of falling into darkest space. Then, in a
moment it seemed, they were stepping into the hall from which they had
fled pursued by the green men--only for the second time, to be
confronted by a crowd of hostile giants. "Don't fire, Kid!" yelled
Ward. "It's no use to kill them uselessly. Give them the bombs!"

Disconcerted by the attack of tear-gas, the green men broke and fled.
"After them," panted Ward: "we've got them on the run!"

* * * * *

Thrilling to the lust of battle, the two Americans emerged into an
open square. They had little time to note the odd buildings and
strange statues. Coming towards them with leveled weapons, the nature
of which they did not know, was a band of short men--that is, short in
comparison with the greenish giants. Behind this company appeared
still another, and another. Tear-gas was useless to stop their onward
rush. "All right," yelled Miles, "it's lead they want!"

The machine-gun spat a hail of bullets. Before the first withering
blast the swarthy men recoiled in confusion. Then a second volley
scattered them like chaff. Miles and Ward were conscious of no pity
for the dead and wounded lying on the pave