Rushing back through the corridor, they collected as many of the crew as were able to move, flung open the heavy doors of the air-lock, and scrambled down to the floor of the cave.

Here and there lay bodies, pirates caught unawares. Suddenly Holden saw a blue flash. One of the mechanics clutched at his breast and fell, dead in an instant.

"Some of these fellows are still alive. They're using ray pistols," Holden shouted into his suit phone.

Even as he spoke he heard the sound of running feet from the darkness in the rear of the cave, where the bow of the Silver Death was barely visible in her cradle, and in a moment at least fifty figures, pirates who had somehow escaped the fatal cold of space, clad in clumsy suits and brandishing pistols, flung themselves desperately upon the smaller party.

Blue flashes were everywhere as the battle commenced, but the only sound was of struggling feet, with an occasional thud as a body hit the floor. The pirates had been weakened by their long stay on the moon, and moved slowly, but the surprise of their attack, and the superiority of numbers had given them some advantage. It was man to man fighting, savage and merciless.

Holden, with a neat dive, knocked the feet from under a huge fellow who had trained a pistol on him, and they rolled over and over, each trying desperately to gain a second's advantage. He heard a dull crash to one side, as Captain Linet, jumping high into the air, landed with stunning force on a bewildered assailant. Thinking of Jean, waiting for him in some dim corner of the cave, he redoubled his efforts.

For a fraction of a second his pistol pointed toward his antagonist's body, and that was enough. He pressed the release, and the deadly ray shot into the body beneath him, dealing instant death. Freeing himself from the cold grip, he ducked an empty pistol flung at him by a new assailant. Again his finger bent, and another body dropped to join those lying motionless on the floor.

A fast-moving shadow caught his eye. He saw one of the pirates detach himself from a writhing group and head for the side of the cave. That was the place where Jean had said she would be waiting!

Pausing only an instant to make sure that his pistol was still charged, Holden sprang in pursuit of the fleeing form. He saw him stoop and pick up a heavy bar from the floor. The coward was going to burst open the chamber where the helpless captives waited! It was impossible to aim at that speed, so Holden forced his flying feet to move still faster, and foot by foot he drew closer to the man he pursued. Metal plates again gleamed in front of him, and he saw the pirate raise the bar high over his head, preparing for a blow which would crush the thin plates. The tiniest hole would mean death to the captives, who had no means of protecting themselves.

With one last desperate effort, Holden jumped, his Earth-trained muscles carrying him high into the air, while his pistol stabbed the partial darkness with vivid rays. Dodging and ducking, the pirate evaded the fatal stabs, while his bar beat a loud tattoo against the metal. Holden struck at him with his now useless pistol as he landed. The blow missed, and, losing his balance, he staggered and fell, past his foe, who quickly turned, raising his bar for a coup de grace which never landed. The familiar flash of a pistol once more illuminated the scene, the bar dropped from dead hands, and Holden scrambled to his feet.