In 1842 England , a young boy builds a snowman , but refuses to play with the other children . The snowman starts speaking to the boy , repeating his assertions that the other children are silly . Fifty years later , the boy has grown up to be Dr. Walter Simeon , proprietor of the Great Intelligence Institute . He hires men to collect samples of snow , which he places in a large snow @-@ filled globe in his laboratory before feeding the men to a group of animated snowmen . The Doctor , still despondent after losing his former companions Amy Pond and Rory Williams , has parked his TARDIS above Victorian London among the clouds . He uses his allies Vastra , Jenny , and Strax to keep people away from him . They also fill their time investigating mysteries throughout the city .