"After them!" commanded Placer. "But stay together. We'll have to try to hunt them down in the vats, and maybe the Toughs can help us, but we don't want to get separated so they can pick us off one by one."

"Wait, Placer, there's something you ought to know," said one of the two Masters who had come from the direction of the conference room. "Greyde called out a few minutes ago to tell us he had word from Vidonati in the control room. Those groundcars that were hanging around had attacked one of the entrance buildings."

"Space!" growled Placer. "There must be a conspiracy involved here somewhere. We'd better stay up here, then."

He pulled the lever beside the gate to the ramp, and it rumbled down and crashed into place.

"At least, those two are trapped below," he said with satisfaction. "We can hunt them down at our leisure when we've repelled this attack from outside. If we can take them alive, I'm of a mind to make them pay well for their responsibility in our losing all our experimental Jellies."

The seven of them went on to the conference room, picking their way among the bodies of the Jellies. Placer took over the intercom from Greyde.

"Vidonati, this is Placer," he said. "What's the situation?"

"The groundcars attacked the south building," replied Vidonati. "They moved in and concentrated all three car beams on the airlock and burned it through. I counted nine men in marsuits who left the groundcars and went into the building. Of course, as soon as they started blasting the airlocks, I closed the emergency barrier to block off the downward ramp."

"Obviously, since we still have air in the place," commented Placer dryly. "You'd better call Mars City and get them to send help."

"I've already done that," said Vidonati. "A jet squadron's on its way."

"Good," said Placer. "They can be here in about five hours, and it will take those rebels, or whoever they are, two or three times that long to burn through one of the emergency barriers, even if they blast an opening and bring their groundcars into the building to bring the groundcars' big guns on it."

"Should I stick it out here, or seal all the barriers and come below?" asked Vidonati. The control room was in the north building.

"Stay up there so you can report on what they're doing, unless they start to move toward that building," instructed Placer. "If they do, seal the other emergency barriers at once and come below. We can switch to the emergency radio down here to keep in touch with the task force from Mars City, and just wait it out underground until they clean up these rebels."

"Good enough," agreed Vidonati. "I won't take any chances."