Li Chen Mei was a Chinese woman living in Sydney during part of World War II. She worked as a fortune teller, making herself up as an older woman to gain her customers' trust. She was acquainted with the Doctor.
Mei was a guardian of the "hymnal skein".
During the chaos following a Japanese submarine's torpedoing of an American warship, the Seventh Doctor and Ace called on Mei. She made them tea, then gave the Doctor the box that he had come for. After they left, she had dreams of the Doctor trying to tell her something. She finally realised he was telling her to go to Mrs Harris' house. Mei made her way there, where she stopped Mrs Harris from manipulating the "life force". She then explained to Mrs Harris that though she could sense the skein, she didn't have the ability to manipulate it. (PROSE: Hymn of the City)