In New York Times bestselling author Rebecca Cantrell's sequel to the award-winning The World Beneath, software genius, Joe Tesla, confronts an equally brilliant and far more powerful foe. Still crippled by agoraphobia and confined to the tunnels under New York City, Joe is haunted by the fact that he cannot even attend his father's funeral.

His father's death brings threats to the safety of Joe's underground home: guilt over the broken relationship that can never be healed, a mysterious box of papers inherited from eccentric inventor Nikola Tesla, and a ruthless enemy determined to steal those papers no matter the cost. Mystified by why his inheritance is so valuable, Joe and his service dog, Edison, follow clues left a century ago by Joe's famous ancestor to reveal the power of his family legacy. While Joe must rely on his considerable talents as a hacker, he must also reach out to friends. But whom can he trust as he battles to save his beloved city from . . . The Tesla Legacy?