Magic leaves the Wild Thicket, where the magical people live. There is only one way to get her back - by stealing a human baby and leaving a goblin shifter in his place. Under the cover of darkness, the goblin Cull sneaks into the house of Annie and Joseph Burton, but everything goes awry, and the parents discover not one, but two completely identical babies in the cradle! Thirteen years later, twin brothers Tinn and Cole receive a strange letter: it says that The changeling must return to his relatives as soon as possible, otherwise he and the entire magical people will disappear from the face of the earth. But which brother are we talking about? The boys have no choice but to go on a journey together through the dangerous Crooked Swamp...