'A Study in Scarlet' Summary

In 1881, Doctor John Watson has returned to London after serving in the Second Anglo-Afghan War. He visits the Criterion Restaurant and runs into an old friend named Stamford, who had been a dresser under him at St. Bartholomew's Hospital. Watson tells Stamford he is looking for a place to live before his nine-month half-pay pension runs out. 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.

Stamford takes Watson back to St. Bartholomew's where, in a laboratory, they find Holmes experimenting with a reagent, seeking a test to detect human hemoglobin. Holmes explains the significance of bloodstains as evidence in criminal trials. Watson raises their parallel quests to find a place to live. At Holmes's prompting, the two review their various shortcomings to make sure that they can live together. After seeing the rooms at 221B, they move in and grow accustomed to their new situation. Holmes reveals that he is a "consulting detective" and that his frequent guests are clients. Facing Watson's doubts about some of his claims, Holmes casually deduces to Watson that one visitor, a messenger from Scotland Yard, is also a retired Marine sergeant. When the man confirms this, Watson is astounded.