One reckless decision can change a life. David Sandoval is a sixteen-year-old genius, more content with studying than being with family or friends. When he is abducted by a gypsy caravan owned by a living Grecian sphinx, he is taken on an adventure through the Curtain, the gateway between our world and the worlds of the "unseen," where many creatures of myth and legend reside. After discovering that he has unwittingly proposed to the sphinx, David attempts to escape back through the Curtain to the human world, only to be sent to Kyoto, Japan, where he learns a dark secret: a Shade, an extension of the shadowy Night Goddess Nyx, is slowly draining the sphinx of her most precious talents. David might be the only human on earth with the knowledge to save her, and he must also save his new friends from a ruthless adversary known as the Teumessian. Can one normal boy truly undo the inflictions of a goddess, and rescue both the seen and unseen worlds from her dark intentions?

The fight to save the world is just beginning. Waking on the outskirts of Le Havre, David has no memory of his past or who he’s left behind. Nyx has erased his existence, but there is hope: face the mysterious Moirai, the weavers of the Curtain, and have a new fate woven. With old enemies on his trail and no one in the human world able to see or hear him, he must traverse the places and people of the past to regain his memories before everything falls under Nyx’s shadow.

David thought his days of fighting monsters were over. After two years of peace with his wife in Paris, a new danger has emerged. The world-devouring creature Fenrir has broken free of his prison, intent on finding Acacia and taking back what she possesses. That isn’t the only evil afoot… Rumors abound that an old adversary has returned, and madness itself seeks to claim David. Yet those enemies are nothing compared the new incarnation of Nyx, who will stop at nothing to use Fenrir’s abilities to destroy the world. With time running out, David must band together with old friends and new allies to save both the human world and the world of myth and legend.