“Somebody’s coming, but suppose it’s the Patrol?”

“If so, a few blasts won’t hurt ’em—they’ll be in G P armor.” Cloud did not add that Graves would probably rush his nearest thugs in just as they were; to kill the two witnesses before help could arrive.

The first detachment to round the corner was in fact unarmored. Cloud’s weapon flamed white, followed quickly by Ryder’s, and those zwilniks died. Against the next to arrive, however, the DeLameters raved in vain. But only for a second.

“Back!” Cloud ordered, and swung the heavy door shut as the attackers’ beams swept past. It could not be locked, but it could be, and was, welded to the jamb with dispatch, if not with neatness. “We’ll cut that trap-door off, and stick it onto the door, too—and any more loose metal we can find.”

“I hope they come in time,” the girl’s low voice carried a prayer. Was this brief flare of hope false? Would not only she and her Bob, but also their would-be rescuer, die? “Oh! That noise—s’pose it’s the Patrol?”

It was not really a noise—the cell was sound-proof—it was an occasional jarring of the whole immense structure.

“I wouldn’t wonder. Heavy stuff—probably semi-portables. You might grab that bucket, Bob, and throw some of that water that’s trickling in. Every little bit helps.”

The heavy metal of the door was glowing bright-to-dull red over half its area and that area was spreading rapidly. The air of the room grew hot and hotter. Bursts of live steam billowed out and, condensing, fogged the helmets.

The glowing metal dulled, brightened, dulled. The prisoners could only guess at the intensity of the battle being waged. They could follow its progress only by the ever-shifting temperature of the barrier which the zwilniks were so suicidally determined to burn down. For hours, it seemed, the conflict raged. The thuddings and jarrings grew worse. The water, which had been a trickle, was now a stream and scalding hot.

Then a blast of bitterly cold air roared from the ventilator, clearing away the gas and steam, and the speaker came to life.