I jammed the "stand clear" warning to the bridge and shot a hasty query back to the Slipstream operator.

"Saturn standing clear, pal. What makes?"

"Trouble on declension line sixteen-oh-four. Stay off our trajectory! We're running into a vac—"

Then suddenly the message went dead; the condenser needle went to sleep on zero; I was hammering a futile key at an operator who could no longer communicate with me.

But I knew what the trouble was. Our streamlined rival had nosed into a space vacuole!

By this time, the Saturn was creaking and groaning like a jitterbug on a coil-spring mattress; bells were dinging all through the runways, and the forward blast jets were making an unholy din as they bounced us off trajectory. And every time one exploded, of course, the lugger shook as if a gigantic fist had smacked it square in the nose.

Footsteps pounded up the gangway, the door opened, and I had visitors. Cap Hanson, Diane Hanson, and our acting Skipper, Lancelot Biggs. They all hollered at once.

"What is it, Sparks?"

"Vacuole!" I snapped. "The Slipstream broke into one. They're preparing for the back-drag now."

Diane Hanson's eyes were like twin saucers.