The story marks the first appearance of Sherlock Holmes and Dr. Watson. In part I, the story begins in 1881, with Dr. Watson returning to London after serving in the Second Anglo-Afghan War, visits the Criterion Restaurant and runs into an old friend named Stamford, who had been a dresser under him at St. Bartholomew's Hospital. Stamford mentions that an acquaintance of his, Sherlock Holmes, is looking for someone to split the rent at a flat at 221B Baker Street, but he cautions Watson about Holmes's eccentricities. In part II, the story moves to the Salt Lake Valley in Utah in 1847, where John Ferrier and a little girl named Lucy, the only survivors of a small party of pioneers, lie down near a boulder to die from dehydration and hunger. They are discovered by a large party of Latter-day Saints led by Brigham Young. A Study in Scarlet was the first work of detective fiction to incorporate the magnifying glass as an investigative tool.