the doorway. It was only
a gentle push: Chet wondered as he saw the man stagger and grasp at his
throat. He was coughing--choking horribly for an instant outside the
open port--then fell to the ground, while his legs jerked awkwardly,
spasmodically.

Chet saw Kreiss follow. The scientist would have leaped to the side of
the stricken man, whose body was so still now on the sunlit rock; but
he, too, crumpled, then staggered back into the room. He pushed feebly
at the port and swung it shut. His face, as he turned, was drawn into
fearful lines.

"Acid!" He choked out the words between strangled breaths.
"Acid--sulfuric--fumes!"

* * * * *

Chet turned quickly to the spectro-analyzer: the lines of oxygen and
nitrogen were merged with others, and that meant an atmosphere unfit for
human lungs! There had been a fumerole where yellowish vapor was
spouting: he remembered it now.

"So!" boomed Schwartzmann, and now his squinting eyes were full on Chet.
"You--you _schwein_! You said when we opened the ports there would be a
surprise! Und this iss it! You thought to see us kill ourselves!

"Open that port!" he shouted. The men who held Chet released him and
sprang forward to obey. The pilot, Max, took their place. He put one
hand on Chet's shoulder, while his other hand brought up a threatening
metal bar.

Schwartzmann's heavy face had lost its stolid look; it was alive with
rage. He thrust his head forward to glare at the men, while he stood
firmly, his feet far apart, two heavy fists on his hips. He whirled
abruptly and caught Diane by one arm. He pulled her roughly to him and
encircled the girl's trim figure with one huge arm.

"Put you _all_ on one island?" he shouted. "Did you think I would put
you _all_ out of the ship? You"--he pointed at Harkness--"and you"--this
time it was Chet--"go out now. You can die in your damned gas that you
expected would kill me! But, you fools, you imbeciles--Mam'selle, she
stays with me!" The struggling girl was helpless in the great arm that
drew her close.

Harkness' mad rage gave place to a dead stillness. From bloodless lips
in a chalk-white face he spat out one sentence:

"Take your filthy hands off her--now--or I'll--"

Schwartzmann's one free hand still held the pistol. He raised it with
deadly deliberation; it came level with Harkness' unflinching eyes.

"Yes?" said Schwartzmann, "You will do--what?"

* * * *