The Doctor picks up Clara and takes her back to Latimer 's mansion , placing her under medical care of Strax . He collects the ice fragments from the governess and places them in a souvenir London Underground biscuit tin . He and Vastra travel to Simeon 's lab , where the Doctor notes the Intelligence 's plan to replace humanity with ice creatures and holds up the tin with the necessary DNA . Dr Simeon grabs the tin and opens it only to find the memory worm , which latches on to him . The Doctor states that the Great Intelligence , which has been existing as a mirror of Dr Simeon 's thoughts , will vanish with the erasure of Simeon 's memories . Instead , the Intelligence reveals that it existed long enough that it can now control Simeon 's body , which it uses to attack Vastra and the Doctor . The influence of the Great Intelligence quickly wanes , and Simeon falls dead . Outside , a salt @-@ water rain has started , and the Doctor sees that another psychic ability has taken control of the snow from the Great Intelligence : the Latimer family , crying for Clara . Strax informs the Doctor upon his return to the Latimer mansion that Clara only has moments left , and she passes away as the Doctor returns the TARDIS key to her . At her funeral , the Doctor reads Clara 's full name on her tombstone and realises she is the woman he met in " Asylum of the Daleks " who became a Dalek , whom he refers to as " Soufflé Girl " . He gleefully announces that a person dying twice is an impossibility and , bidding farewell to his allies for now , the Doctor departs in the TARDIS to investigate and find Clara . The episode concludes in contemporary times , where a young woman resembling Clara walks through the same graveyard , pausing by Clara 's tombstone .