On the frozen planet Eedor, 39 light years from Earth in the Trappist-1 system, a group of children have lived their entire lives underground — raised by AI robots in a technologically advanced cave. They know nothing of their origins, guided only by a voice recording and a recurring ritual called the Pilgrimage: a journey to a hollow mountain summit where they wait beneath the auroras for a message that never comes. Aurora and her companion Neemo are about to uncover the secrets their cave has been keeping.