Sert said proudly, "And you underestimate our people, Larry Wilson. The news of this battle will spread, and before the next work-period thousands will flock to our standard. We will build more sonic machines, perhaps portable ones, and—"

"Sure. And what are the Masters going to be doing while all this goes on? I'll give even money that right now they're herding in the Underlings from other parts of this city for a little wholesale slaughter. It is a city, isn't it?"

"Yes. One large city-state under a single impervite dome operated from a control chamber."

"Operated?" repeated Larry.

"But, certainly. It can be opened for fresh air to be admitted, or for the egress and entrance of aircraft—"

"Larry!" It was Sandra who interrupted. "There's our answer, Larry. Life is impossible without the protection of the dome. Whoever possesses the dome control chamber holds the whip hand. We must take that!"

Sert's face brightened. "She is right, Larry Wilson. We must take the dome chamber—"

"Wait a minute!" Larry had been thinking swiftly. "Sandy's got something there. But there are angles. First of all, we've got to seize the control chamber, yes. But we also need more men. If we don't get reserve strength—and good, strong fighting men, at that—sooner or later they'll starve us and our little rebellion right out of our cubby-holes.

"Right now the odds are temporarily balanced. We have fewer men, but our men are more powerful. Theirs are the best weapons, but our single weapon makes theirs useless. They control the dome—a point in their favor. But we are fighting for life and freedom—a point in ours.

"So it's a stalemate. And one that will turn into defeat for us unless we move swiftly. Before they recognize our pitiful weakness." He gazed sharply at Sandra. "Sert is needed here, to rally recruits. So it's up to you and me to get control of the dome chamber. I see one way to win. It's a dangerous way, but—"