The journey that never ends. The heroes who never die. The number of worlds that will never be counted.

The story begins with Artemia disappearing after a quarrel between two friends. Feeling guilty, Catherine finally decides to find her. Her search leads her to discovering another world, and her friend Artemia turns out not to be so simple as she seems. Her family's story is deeper and more tangled. The old expedition of Charles Ervin is more mysterious, and Catherine's university holds its own secrets.