The Adventure of the Empty House

Ronald Adair, a quiet young man whose only hobby was playing cards, has been killed. Watson attempts to crack the case, but with no success. One day, he decides to examine the area around the victim's house and runs into a strange old man. Who is he? Could he be the murderer who has returned to the crime scene in disguise? Or is the old man simply a witness? Will Watson find out what happened by applying Holmes's methods, or will this not be enough? You can find the answers in "The Adventure of the Empty House", which is part of "The Return of Sherlock Holmes".