Thus, playing a grim game of hide and seek, they finally made their way up to the control room. But here they ran into a huge, massed group of the Sediphrons, who had evidently been ordered to await any such move on the part of the desperate fugitives.

The lurid crackle of electronic bolts fused against the corridor walls. Storm and Hammond worked their rifles with grim methodicalness, blasting a half dozen of the green crustaceans into oblivion. But there were too many of them. They had to fall back along the corridor.

Then Ardiné received a partial shock from a glancing bolt that dropped her. Storm sprang for her, heedless of the bursting bolts, and caught her up in his strong arms. Gena and Hammond covered him under a steady flare of bolts.

With Storm ahead of them they turned and ran.

It was up to Gena. The Earthmen followed blindly, lost in the bewildering maze of ramps, rooms and corridors.

As if in a grim nightmare they fought their way back through the ship, escaping annihilation many times by Gena's unerring knowledge of dilating doors that gave temporary safety.

Once Hammond saw Gena glance down at her chronometer, and he felt the rise of alarm in her thoughts before she blanked them out. And the chemist remembered then the time-bomb she had planted in the degravitator room of the Vandar III.

They crossed a momentarily deserted corridor, Storm still carrying the unconscious Ardiné, and went into a long room that held a maze of long metal pipe overhead and squat machinery with smaller feeders leading up to the huge conductors.

Gena's thoughts came to Hammond as they paused here. "If we must die, let us at least take Zuggoth and his hideous horde with us. I can't let them get back to Mars now."

Hammond said: "Gena! Wait!"