Shadowrise (Shadowmarch Series #3)

A year ago, the March Kingdoms were at peace, the Eddon family held the throne, and all was right in Southmarch Castle. Now the family has been shattered. King Olin Eddon is a prisoner and his heir is slain. The royal twins Barrick and Briony have done their best to hold the kingdom together, but now Barrick has been captured and Briony has been forced to flee the castle. Old magics are stirring beneath the ancient castle and behind the Shadowline, and the machinations of gods, fairies, and mortals threaten to spread devastation across the entire world.