poɔʇoɹ ʍɥo: perception

Something is in the Doctor's head, corroding him from the inside until there's nothing left. No memories, no regenerations, nothing. Clara is sent into the Time Lord's mind to save him before it's too late, but not without the help of the only other people in the universe he would ever depend on to save his life, himself. Set between Kill The Moon and Mummy on the Orient Express.