In the city of Gis, the king lives in a golden hall and the people do not want anything. Everyone is happy and everyone is rich. Or at least it seems so. When the Doctor, Amy and Rory get to the bottom of it, they discover a veritable realm of secrets. Strange creatures live in dark corners. In the heart of the hall, the golden dragon exudes gold. Then a messenger appears, demanding the return of his treasure... And ships fly after him. The battle for the treasure begins, and only the Doctor and his friends can save the city's inhabitants from dying in the crossfire of an ancient civil war. But will the king give up his new valuable acquisition? Or will he fight for it?