Merlin: 5x1

Arthur's Bane - Part 1

Camelot faces a new golden age, but even as the city flowers, the dark seeds of destruction are being sown. In the frozen wastelands of the north, men are disappearing without a trace. King Arthur and his knights undertake a dangerous mission into the unknown in search of answers – but once there, Merlin finds himself locked in a battle unlike any he has fought before.