Horace F. Andrews, armed with a strange wooden box, and Chloe Burke, wearing a mysterious dragonfly pendant, become entangled in a secret and ancient society striving to protect powerful devices from the evil Riven.
While Horace and Chloe struggle to master new powers under the shadow of a rising adversary who threatens all Keepers, a faraway new Keeper, April, travels with a mysterious woman in the hope of fixing her damaged Tan'ji magical object.
