To mortal eyes, the Toybox Coffee Shop is just another cafe. But to San Francisco's changelings, it's a haven where they may abandon their mortal guises. An unlikely group of companions—a waitress, a nomad, a street performer, a tramp and two children—band together to prevent the wizard Malacar from claiming vengeance.

The six oathmates, sworn to each other and to the completion of a quest, search for four powerful faerie treasures that open a lost gateway back to Arcadia. Backed by the forces of the Unseelie Shadow Court, the Forsworn Prince also seeks the way back to Arcadia, for his own dark purposes.

One of the changelings' own has betrayed them. Now he sails to Ireland, ancient home of the sidhe. The remaining oathmates must follow in search of the fourth and final Eyestone, for whomever unites the four gems will discover the secret of the Court of All Kings and open the last passageway to Arcadia.