Robot of Sherwood

Clara is offered the chance to choose the next destination for herself and the Twelfth Doctor. They go and meet the English folk hero Robin Hood, much to the Doctor's disbelief in the existence of someone who's supposed to be a mere folk story character. Travelling through Sherwood Forest in 1190, they soon realise that something is amiss, as the cruel Sheriff of Nottingham and his malevolent robot knights set in motion a plot that could rewrite the course of history for the worst.