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On 24 December, a Christmas EveCinderellapantomime was held in a newly-opened theatre. The Addos, who had been dormant beneath the site of the theatre since 1902, were woken up. To get power, they tried to recreate a mummers play by altering the DNA of the actors so their faces naturally resembled animal masks. When the audience became horrified, the Addos froze everybody. The Twelfth Doctor arrived in the theatre and entertained the crowd with the help of an actress. The Addos fed off the entertainment and were able to get enough power to leave Earth. (PROSE: Behind You)
When the Eleventh Doctor ejected a room from his TARDIS, it accidentally created a time corridor from 2014 to 1964. He came to end of corridor in 1964 with Clara Oswald and closed it after sending two children who had walked through the corridor back to their own time. (COMIC: The Door to Winter Long Ago)