 Acting on a tip from <unk> , the Doctor visits the Great Intelligence Institute posing as Sherlock Holmes . He confronts Dr. <unk> and find a large glass globe in <unk> 's office that contains psychic snow . The Doctor speaks to the Great Intelligence , the entity that has been speaking to Dr. <unk> since he was a boy . He learns that the Great Intelligence has been controlling the <unk> and has taken interest in <unk> 's pond . The Doctor visits the pond and <unk> that the Great Intelligence is using the old governess ' body as a DNA <unk> to form an ice creature that will retain its form and not melt . While <unk> is putting the children to bed , the frozen body of the governess breaks into the house . The Doctor fights her off and is joined by <unk> , Jenny and <unk> . Dr. <unk> arrives with more <unk> and tells them he wants the governess ' ice body . The Doctor flees with <unk> to the roof of the mansion and then to the <unk> <unk> overhead . They are pursued by the ice governess , whom the Doctor traps under a layer of frozen ice crystals . Inside the <unk> the Doctor gives <unk> a <unk> key , but the ice governess arrives and pulls <unk> down off the cloud . 
