I'm Just Imprinted All Over Your Sofa. No, They're Not Ghosts

Cliff Archibald was checking the CCTV monitors in his office after Bank Monument station had been emptied and closed. At 2am, he noticed something strange - a little old woman dressed all in black was standing in the middle of a corridor. She looked up at him, turned, and moved into one of the side corridors. When he reached the corridor that she'd walked into, she was nowhere to be seen. Sarah Whitehead spent 25 years returning daily to the bank area, dressed in black, to mourn the death of her executed brother in 1811. It is believed that her grave was disturbed in the building but she's apparently seen really regularly.