The 2012 Eleventh Doctor (Matt Smith) episode "The Snowmen" provides an origin for the Great Intelligence, whose voice is provided by Sir Ian McKellen. It reveals that the Intelligence originated as a crystalline organism that looks like snow and responds to the thoughts of others. The snow-like organism became influenced by the thoughts of a young boy, Walter Simeon, during the 1800s, forming a mental symbiosis. From there, the Great Intelligence had the adult Dr. Simeon (Richard E Grant) create "The Great Intelligence Institute" and orchestrate a scheme to obtain the DNA of a governess who froze to death in the Latimer family's pond. He intends to use her DNA to create ice-based lifeforms incapable of melting to take over the world. After the ice creature is destroyed, the Doctor uses a "memory worm" on Dr Simeon to erase his memories, expecting this to destroy the Intelligence. However, the Great Intelligence has existed long enough to become an independent entity and uses Simeon's brain-dead husk to attack the Doctor before withdrawing from his vessel when the Latimer family cries for the dying Clara, triggering his snow to melt. It is implied these events lead to "The Web of Fear" as the Doctor shows a map of the London Underground from 1966 to the Great Intelligence.