Robert Downey Jr. stars as the legendary London sleuth Sherlock Holmes, joined by Jude Law as dear Dr. Watson, in this Guy Ritchie reinvention of Sir Arthur Conan Doyle's oft-adapted detective series. Based on a comic book by producer Lionel Wigram, the story follows Holmes and Watson as they face off against the villainous Blackwood (Mark Strong). Rachel McAdams co-stars as quick-witted beauty Irene Adler.