Tragedy of X — Ellery Queen

A retired Shakespearean actor plays his new role -- amateur sleuth -- after a murder in a New York streetcar.

Born during intermission in a seedy New Orleans playhouse, Drury Lane has spent the better part of his life in the theater. A majestic old-fashioned ham, he made his name in London, where his record-breaking run as Hamlet defined the role for a generation. When hearing loss forces him to retire, he turns his attention to human drama -- specifically crime. Using his powers of disguise, knowledge of human nature, and an occasional dash of theatrical combat, Lane is the most fantastic detective of all time -- onstage or off.
 
In The Tragedy of X, a man is poisoned in the middle of a crowded New York streetcar, and not one of the dozens of witnesses can provide any useful evidence. The police are stumped until they receive a letter from Lane, claiming to have solved the crime by reading newspaper reports. He knows the killer's name -- but now he has to catch him.