become
poisonous through the Earthmen's slow breathing. But the Martian had
anticipated Darl's final move. The oxy-hydrogen jet of the welding
machine the dwarfs were hoisting would make short work of their final
defense.

* * * * *

From the conning-tower above Ran-los called excitedly. Through all the
long battle the Venusian had remained steadfast at the peri-telescope,
scanning the vacant terrain outside, and the heavens. As Darl and Jim
dashed for the stairs Mac ran after them, crying out, "What did he say,
mon?"

"Space ship in sight," Darl flung over his shoulder as he reached the
upper landing.

"Praise be! Noo the haythan weel get his desairts!"

"Yeah, maybe--if it's an Earth ship. But we won't be here to see it."

Jim's red head was bending over the peri-telescope view-screen. "She's
still thirty thousand miles away. Give her a speed of fifteen per
second--she'll have to slow up to land, can't make it under forty-five
minutes. By then we'll be in little pieces. It took me ten minutes to
burn through the barrier when I rescued Darl, and it won't take the
Mercs any longer to get at us."

Darl was very sober as he looked on with narrowed eyes. Against a
background of velvet black, gold spangled, the slim space-traveler
showed. The sun's rays caught her, and she was a tiny silver fish in
the boundless void.

"Luik ye, mon, luik ye!" Angus, fairly dancing with excitement,
elbowed Darl aside. "She's from Airth, richt enow!" At the nose of the
oncoming flier a rapid succession of colored lights had flashed, the
recognition signal that should give her safe access to the Dome. Again
there was a coruscation of coded flashes. "She's a battle cruiser,
what's mair!" the Scot exclaimed.

* * * * *

Darl sprang to the keyboard that manipulated the signal lights from
the Dome's roof. "No use," he said, after a short while. "The Martian
has cut off the current from the dynamos. I can't warn the ship." He
made a hopeless gesture.

Jim looked at him wonderingly. "Warn 'em? What for? Even if we are all
dead when she reaches here, at least she'll clean up the Mercs, and
retake the Dome for Earth."

"Don't you see it? When the Mars man has once blasted his way in here
and disposed of us, he'll be ready for the space ship. Her captain
can't suspect anything wrong. He must have left Earth at the time of
the ultimatum, and would easily get here before any