[youtube=http://www.youtube.com/watch?v=q3bGYljQ5Uw]
Months after an encounter with a mysterious ‘Doctor’, Sherlock becomes obsessed with discovering more about this impossible man… until the man makes an unexpected return.
In anticipation of both the Doctor Who Christmas Special and the Third Series of Sherlock, a fan of the series created a small crossover story… and you can watch it in the video.