Ryan and Essie
All his life, 11-year-old Ryan has dreamed of becoming an astronomer, but not, it turns out, of actually going into space. When a public event brings a complete stranger named Essie to the observatory his father directs, Ryan's life will never be the same again--at least, being catapulted into a deadly serious epic adventure certainly wasn't how he had planned for his day to go. When Essie accidentally launches them onto the distant planet of Caricanus, Ryan can't forgive her for stranding him in this bizarre new world with no way to get home. After quarreling, they part ways--Ryan to the mysterious lands where a castle made of rubies collapsed in an ancient war and Essie through the mountains to the hidden valley of the diamond castle. They find themselves on opposing sides of an ancient battle started when humans brought mutant life to Caricanus. Seven mystical pillars hold the answers, but only if the two children can get over their differences.
Extra short story included: The Old Man and His Grandsons.
Death of two characters traumatically affects the protagonists and is central to their journey. No violence or gore.