Humans use strata spaceships to explore deep into the earths interior. A stratum spaceship crashed during the voyage and sank to the center of the earth. There is only one young female navigator on board. She can only spend the rest of her life in the closed center of the earth... This series includes eight short and medium sci-fi stories from Poetry Cloud, Sea of ??Dreams, Ode to Joy, The Thinker, The Devourer, Bring Her Eyes, Earth Fire and Mountain. Galaxy Award Reader Nomination Award Galaxy Award and other science fiction awards. This series explores the deep space of the universe outwards and the inner world inwards, and tells the communication and collision between different species and civilizations.