Arcot dived for the control room, while Morey shut off the telectroscope and put the latest photographs in the file.

Suddenly space was snapping about him—they were off again. Another shock of surging energy—another—the ship leaped forward at tremendous speed—still greater—then they were rushing at top speed, and beside them ran the ghost ships of the Ancient Mariner.

Morey pushed himself into the control room just as Arcot, Wade, and Fuller were getting ready to start for the lab.

"We're off for quite a while, now," he said. "Our goal is about five days away. I suggest we stop at the end of four days, make more accurate measurements, then plan a closer stop.

"I think from now on we ought to sleep in relays, so that there will be three of us awake at all times. I'll turn in now for ten hours, and then someone else can sleep. Okay?"

It was agreed, and in the meantime the three on duty went down to the lab to work.

Arcot had finished the installation of the invisibility apparatus in his suit at the end of ten hours, much to his disappointment. He tested it, then cast about for something to do while Wade and Morey added the finishing touches to theirs.

Morey came down, and when Wade had finished his, which took another quarter of an hour, he took the off duty shift.

Arcot had gone to the library, and Morey was at work down below. Fuller had come up, looking for something to do, and had hit upon the excellent idea of fixing a meal.

He had just begun his preparations in the kitchen when suddenly the Ancient Mariner gave a violent leap, and the men, not expecting any weight, suddenly fell in different ways with terrific force!