The Beekeeper's Apprentice (Mary Russell and Sherlock Holmes, #1)

Long retired, Sherlock Holmes quietly pursues his study of honeybee behavior on the Sussex Downs. He never imagines he would encounter anyone whose intellect matched his own, much less an audacious teenage girl with a penchant for detection. Miss Mary Russell becomes Holmes's pupil and quickly hones her talent for deduction, disguises and danger. But when an elusive villain enters the picture, their partnership is put to a real test.