Riftwalker

Elias Vance is a historian, not a hero. But when his ship falls into a black hole, he wakes up in the past, and every time he nears death the river of time throws him somewhere new. Samurai Japan. The Amazon. Viking Norway. Tesla's New York. In every era he learns a way to fight, and in every era a masked figure in silver armor is already waiting. All he wants is to get home to his wife. Home has secrets of its own.