Credit: Wendell Teodoro/

Elementary, my dear Watson!

Southland star Lucy Liu has signed on to play Sherlock Holmes' sidekick in the pilot for CBS' new drama, Elementary -- but she's not quite the Dr. Watson the books' author, Sir Arthur Conan Doyle, imagined.

The actress, 43, will play Joan Watson, a former surgeon and sober companion to a fresh out of rehab Holmes, in the New York City-based modern day adaptation of the classic detective stories.

Also appearing in the Michael Cuesta-directed pilot: Dexter's Jonny Lee Miller, 39, as Holmes.

Liu, who is the first woman to play the role, will next appear on the big screen alongside Russell Crowe in this year's The Man with the Iron Fists.