Resumo do Goodreads:
Here is an exciting tale of action and suspense, set in the world of tomorrow. As the story opens, two brothers, Jim and Ken Barry, are traveling by space ship from Earth to a new city on the moon. Aboard the space ship they discover a stowaway, young Dig Allen. Almost at once the three youths are plunged into an adventure that threatens to spell destruction for them all.
Dig has set out to find his father, a space scientist who mysteriously disappeared months before. The Barry brothers agree to help Dig. Their search takes them to the "Graveyard of Space" and to Mars. There they meet Old Dorkas, the one person who is able to decipher the last message received from the missing man. Finally, the boys are forced to set out along in an unauthorized space ship. They soon find themselves marooned on a weird, forgotten world at the outer edges of the solar system where unknown to them, their greatest adventure is about to begin!