00E00 - The Next Doctor

The Doctor is in a seasonal mood when he arrives in London on Christmas Eve 1851. There are snowflakes in the air, carol singers in the market square and a generally festive air all around. When a woman in distress calls for him to help her, he arrives to find someone else answering her call and calling himself the doctor. The alternate Doctor seems to know more than he should, dresses like the real Doctor and even has a Tardis - though in his version, it's actually a hot air balloon. While The Doctor sorts out just who this impostor is and why they find themselves in the same time and place, Mercy Hartigan and the Cybermen are kidnapping children to work in building their weapon that will allow them to crown their King.