X的悲剧

The story in the book The Tragedy of X begins with a murder in a crowded trolley bus. A man is murdered in the trolley bus, but no one has witnessed the murderer. In fact, lots of people including the victim's partners dislike him. Afterwards, the ticket seller of the trolley is murdered on the ferryboat to home. All investigations of the constable Sam hit a dead end. However, an old actor Lane asserts that he can find the murderer only by means of Sams description of the case. Can he? Perhaps you can!