"Quick, Damis!" came Lura's voice.

The Nepthalim turned to enter but his gaze fell on the six survivors of Monaill's band.

"In with you!" he cried sharply.

The Terrestrials hesitated but Damis grasped the nearest of them by the belt and threw him bodily into the ship. The others hesitated no longer but clambered in. The Jovians were less than fifty yards away and already deep violet flashes began to come from the tubes they carried.

Damis stooped and grasped one of the dead Jovians. With an effort possible to only two men on Earth, himself and Glavour, he raised the body above his head and hurled it straight at the oncoming Jovians. His aim was true and three of them were swept from their feet. With a mighty bound, Damis sprang through the door of the s.p.a.ce ship and the airlock clanged shut behind him.

The crew of the ship were already in place, awaiting orders. There was no time for instruction and Damis leaped to the control board. He pulled a lever far down and in an instant the entire crew was flat on the floor as though an enormous weight had pressed them down. With a superhuman effort, Damis raised himself enough to cut off the power. The ship shot on through the rapidly thinning air, its sides glowing a dull red. The heat inside the ship was almost intolerable.

As the pressure of the enormous acceleration ceased, the bruised Terrestrials struggled to their feet. Damis turned to another lever and a breath of icy air swept through the ship.

"This will help for an instant," he gasped, "and the cold of s.p.a.ce will soon cool us down. I had to give the ship a tremendous start or the tubes of the Sons of G.o.d would have reduced us to elemental atoms. Keep away from the walls and don't exert yourselves. I can handle the ship alone for the present."

For half an hour the ship charged on through s.p.a.ce. Damis presently pulled the control lever down and placed the ship under power. The walls changed from dull red to black and the temperature in the ship grew noticeably lower. Damis made his way to one of the walls and tested it with a moistened finger.

"It's cool enough to touch," he announced. "Fortunately the insulating vacuum between the inner and the outer skins was at its maximum, otherwise we would have been roasted alive. The external wall was almost at the fusing point. We can move around now."

He posted lookouts at the observing instruments with which the ship was equipped and instructed them in their duties and the manipulation of the instruments. He placed one man at the control lever of the stern rocket-motors. As he turned away from the control board he saw Lura standing quietly in a corner. He opened his arms and she ran to them with a cry of joy.

"Oh, Damis, I was so afraid for you," she gasped, "and I wanted to hug you when you jumped in and Father closed the lock behind you but I knew that you had to take care of the ship. Were you hurt at all?"

"Not a bit, darling," he a.s.sured her, "but it was touch and go for a moment. I didn't know whether the guards would dare to disintegrate the ship without orders from Glavour. In any event, the blasts of the stern motors must have hurled them half a mile. No strength could stand the blast of gas to which they were subjected. Are you all right?"

"Perfectly," she replied; "I never was in any danger. I was the first one in the ship and the only chance I had to be hurt was to have you overcome and the ship recaptured. In that case, I had this."

She displayed a small dagger which she drew from the bosom of her robe.

Damis shuddered and took the weapon from her.

"Poisoned," he exclaimed as he glanced at its tip. "You had better let me take care of it. You might fall and p.r.i.c.k yourself with it."

She surrendered the weapon to him with a smile and Damis placed it in a cabinet built against the wall of the flyer.

"Now go in and lie down," he told her. "I've got to start plotting a course to Mars and teaching my crew how to operate the ship."

"Can't I learn, too?" she objected. "If anything should happen, it might be quite a useful bit of knowledge. Besides, I already understand celestial geography quite well and I may be able to help in the navigation."

Damis looked at her in surprise.

"You a celestial geographer?" he asked in astonishment. "Where did you learn it?"

"From my father. He was a famous heaven-master before the Jovians came and he taught me."

"That's excellent!" cried Damis. "I didn't realize we had so much knowledge at our command. Turgan, will you take charge of the navigating after I plot a course? Lura can a.s.sist you. Now, the rest of you attend to my words and I'll teach you how to operate the rocket motors."

The Jovian ship was built along very simple lines. Batteries of rocket motors at the bow and stern and on each of the sides furnished both motive and steering power. The Terrestrials were all chosen men and in three hours Damis announced himself as satisfied with their ability to operate the ship under any normal conditions. With Turgan and Lura watching and checking his calculations, he plotted a course which would intercept Mars on its...o...b..t.

"Luckily, Mars is approaching us now," he said, "and we won't have a stern chase, which is always a long one. We will be able to reach Mars, spend several days on it and return to Earth before ships can reach the Earth from Jupiter, even if they are already on the way, which is highly probable. I'll turn the ship a little."

Under his direction, the crew turned the ship in its course until it was headed for the point in s.p.a.ce where Damis planned to intercept the red planet. With the course set to his satisfaction, he gave orders for the stern motors to be operated at such a power as to give the highest acceleration consistent with comfort for the crew. There were no windows in the ship but two observers seated at instruments kept the entire heavens under constant observation. Damis motioned one of them to stand aside and told Lura to take his place. She sat down before a box in which were set two lenses, eye-distance apart. She looked through the lenses and gave a cry of astonishment. Before her appeared the heavens in miniature with the entire galaxy of stars displayed to her gaze. In the center of the screen was a large disk thickly marked with pocks.

"The moon," explained Damis. "We are headed directly toward it now but we'll shift and go around it. We'll pa.s.s only a few hundred miles from its surface, but unfortunately it will be between us and the sun and you'll be able to see nothing. Look in the other observer."

Lura turned to the second instrument. A large part of the hemisphere was blotted out by the Earth which was still only a few thousand miles away.

The sun showed to one side of the Earth, but a movable disk was arranged in the instrument by means of which it could be shut off from the gaze of the observer. Despite the presence of the sun, the stars shone brilliantly in the intense black of s.p.a.ce.

"How fast are we traveling?" asked Lura.

"It is impossible to tell exactly," he replied. "I can approximate our speed by a study of the power consumed in our stern motors and again I can approximate it by a series of celestial observations, provided we do not have to change our course while I am doing so."

"Isn't there some sort of an instrument which will tell you how fast we are going?" she asked in astonishment.

"Unfortunately not. We are traveling through no medium which is dense enough to register on an instrument. Our course is not straight, but is necessarily an erratic one as we are subject to the gravimetric pull of all of the celestial bodies. Just now the Earth supplies most of the pull on us but as soon as we approach the moon, we will tend to fall on it and frequent sideblasts will be needed to keep us away from it. Once we get up some speed that is comparable with light, we can measure by direct comparison, but our speed is too low for that now."

"I saw you lay out your course, but how are we steering?"

"The observer who works on the front instrument keeps a cross hair on a fixed star. When the curving of the ship deviates us more than five degrees from our course, a side motor is turned on until we straighten out again. It is quite a simple matter and I'll take the ship myself when we near Mars. There is no need to be frightened."

"I'm not frightened," said Lura quickly; "I was just curious. Is there any danger of hitting a wandering body?"

"Not much in this zone and at this speed. When our speed picks up there will be a slight danger because the higher our rate of speed, the more crowded s.p.a.ce becomes. If we were going to Jupiter we would have to use much more caution. The asteroid belt lying between Mars and Jupiter is really crowded with small bodies but comparatively few are in the zone between Earth and Mars. That is one thing I figured on when I said that we would have plenty of time to go to Mars and back before ships could come from Jupiter. Ships from Jupiter would be able to develop a much higher speed than we will attain were it not for the asteroid belt. They will have to travel quite slowly through it, in portions, not over a few thousand miles per minute, while we are not held down that way. Now that we are really started, it will be best to set regular watches. I will a.s.sign you as navigator for one watch if you wish."

"I certainly do want to do my share."

"All right, we'll let it go that way. Turgan and I will take the other two watches until we get there."

"How soon will that be?"

"About seventeen days. Mars happens to be only about forty million miles away just now. Now I'll set the watches and divide the crew."

A short examination showed Damis that his crew were intelligent and that his instruction had been good. Every member knew his duties. Instead of the two twelve-hour watches which were usual on s.p.a.ce flyers, the additional members of the crew who had been part of Monaill's band enabled Damis to set only eight-hour shifts. Each member of the crew was taught to operate the offensive ray projectors with which the flyer was equipped.

Things soon settled down to routine. No wandering celestial bodies came close enough to cause them any real alarm. Once the novelty of hurtling through s.p.a.ce had pa.s.sed away, the trip became monotonous. The Earth, which had at first filled the field of one of the observers, dwindled until it became merely a brilliant green star. The red speck which was Mars grew constantly more prominent as the hours went by and Damis gave the word to turn on the bow motors and r.e.t.a.r.d the speed of the flyer.

Several of the crew had worked in the communications net which Glavour had thrown around the Earth and under orders from Turgan, they began to call the red planet on the ship's communicator.

"It is well to let them know who we are," he said to Damis when he gave the order. "We are flying a Jovian ship and since we have come so far successfully, I have no desire to be blasted out of s.p.a.ce by their powerful weapons of defense."