siren, with no one thinking to shut it off, was screaming with its electrical voice.
Grantline, stricken for that moment of inactivity, stood gazing. One of the figures broke away from the other, bounded up to the summit from the stair-platform to which they had fallen. The other followed. They locked together, swaying at the brink. For an instant it seemed to Grantline that they would go over; then they surged back, momentarily out of sight.
Grantline found his wits. "Stop them! I'll go out to stop them! What fools!"
He was hastily donning one of the Erentz suits which stood at the lock entrance. "Shut off that siren, Franck!"
Within a minute Grantline was ready. The duty-man called from the window:
"Still at it! By the infernal, such fools! They'll kill themselves!"
The figures had swayed back into view, then out of sight again.
"Franck, let me out."
Grantline was ready. He stood, helmet in hand.
"I'll go with you, Commander."
But the volunteer was not equipped. Grantline would not wait.
"I'm going at once. Hurry, Franck."
The duty-man turned to his panel. The volunteer shoved a weapon at Grantline. "Here, take this."
Grantline jammed on his helmet.
HE moved the few steps into the small air-chamber which was the first of the three pressure locks. Its interior door-panel swung open for him. But the door did not close after him!
Cursing the duty-man's slowness, he waited a few seconds. Then he turned to the corridor. The duty-man came running.
Grantline took off his helmet. "What in hell—"
"Broken! Dead!"
"What!"
"Smashed from outside," gasped the duty-man. "Look there—my tubes—"
The control-tubes of the portes had flashed into a close-circuit and burned out. The admission portes would not open!
"And the pressure controls smashed! Broken from outside—!"
There was no way now of getting out through these pressure-locks. The doors, the entire pressure-lock system, was dead. Had it been tampered with from outside?
As though to answer Grantline's amazed question there came a chorus of shouts from the men at the corridor windows.
"Commander! By God—look!"
A figure was outside, close to the building! Clothed in suit and helmet, it stood, bloated and gigantic. It had evidently been lurking at the porte-entrance, had ripped out the wires there.
It moved past the windows, saw the staring faces of the men, and made off with giant bounds. Grantline reached the window in time to see it vanish around the building corner.
It was a giant figure, larger than a normal Earth-man. A Martian?
UP on the summit of the crater the two small figures were still fighting. All this turmoil had taken no more than a minute or two.
A lurking Martian outside? The brigand, Miko? More than ever, Grantline was determined to get out. He shouted to his men to don some of the other suits, and called for some of the hand bullet projectors.
But he could not get out through these main admission portes. He could have forced the panels open perhaps; but with the pressure-changing mechanisms broken, it would merely let the air out of the corridor. A rush of air, probably uncontrollable. How serious the damage was no one could tell as yet. It would perhaps take hours to repair it.
Grantline was shouting, "Get those weapons! That's a Martian outside!
