Brigands of the Moon
by Ray Cummings
Two planets collide for a lunar treasure! Gregg Haljan was well aware that there were some dangers in the giant Planetara spacecraft that stood on the Moon to receive a special cargo of Grantline's lunar ore. Because this rare metal – invaluable in supporting Earth technology – has been the target of many greedy eyes. However, he didn't understand how intelligent Martian robbers would benefit from a special turn. So when he suddenly found both the ship and himself in their hands, he knew there was only one way he could hope to save that cargo and his own secret, that the space pirate would transform himself and return the moon's robbers back to his own interplanetary currency. Here is a science fiction classic, fascinating and brilliant enough that only a master of superscience can write.