Lehena (Dalek duplicate)
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A Dalek duplicate Lehana convinced Susan Foreman to go back in her personal timeline to get the Hand of Omega. She helped the Daleks bypass the time lock the Time Lords put on the planet. The Eighth Doctor recognised her as the real Lehena was in the year above at the Time Lord Academy as he had a crush on her. (AUDIO: The Shoreditch Intervention)