Dolph Haertel had made history. An incredible anti-gravity discovery, made entirely through his own efforts, had put him miles ahead of the professionals in the space race - and now he was setting off to prove his theories by travelling alone to Mars! The journey went perfectly - until Dolph actually landed on the Red Planet. There, he discovered a fault in his ship that couldn't be repaired without a vital - and missing - spare part. And Dolph Haertel, first Martian explorer, was marooned. His situation was critical. And his only hope lay with the one person to whom he had confided his secret of space travel. But would that person be able to find him in time . . . ?