Professor River Song meet a race known as the Discordia - time-travelling bandits with little regard to the laws of time. Looking like demons, they go around changing history to suit their needs and it seems as though River is the only one who notices. Things only get worse when one of them develops a crush on her.
Michelle Ryan reprises her Dr Who television role as Lady Christina, who comes from a rich background and she spends her time being one of the most successful cat burglars on the planet.