Riddle, A. G. Long winter #3

"Can humanity survive on a new world? The last survivors of the human race escaped a ruined Earth. Their new homeworld--Eos--seemed perfect at first. Warm. Hospitable. Safe from the grid. But everything isn't as it seems. The first colony of settlers--from the Carthage--have disappeared. Their settlement is still there, but everyone is gone. As James digs into the mystery of the lost colony, he discovers a series of spheres, buried on Eos. Are they the key to finding the lost colonists? Or are they responsible for their deaths? Just as James is unravelling the secrets of the spheres, a storm hits Jericho City. Emma, recently elected mayor, struggles to lead her people to safety while James tries to make his way home. In the middle of the chaos, a new danger emerges--a threat no one saw coming. With time running out to save the colonists, James and Emma face their hardest choice yet."--Provided by publisher