Ellery Queen challenges you to solve these clues to death. A thin envelope--worth a man's life. A shattered display case--whose stolen contents a thief replaced with a strange manuscript. The murder symbol: 3HS wM-...the queer cipher found to be an old mark of death. These are but a few of the baffling signs Drury Lane follows down a path of deception and murder to one of the most startling climaxes in mystery fiction!
Cornered! The roadster screeched to a halt. A Cadillac was blocking the road. Suddenly a masked figure leaped from the big car, a gun in its hand. Patience Thumm screamed, then struggled to open her car door. But the gun came down sharply on her knuckles. "Give me the letter," the masked figure commanded.

When Inspector Thumm was given a thousand dollars to guard a letter, he thought that someone was playing a practical joke. But when a masked stranger threatened his daughter, the inspector knew he had been handed a case loaded with intrigue and death.

Reverting to a third-person narrative, possibly the most intriguing and gripping plotline of the series, full of surprise twists, reverses, and inexplicable events. Although a key clue is dropped rather unsubtly but nobody in the story picks up on it until long after the reader catches on. There are loose ends and unexplained developments here and there that never do get dealt with. And the "startling" identity of the murderer, in the back of the alert reader's mind from the first chapter, becomes less and less startling as the story proceeds. It's a tricky matter to the solution logically rather than through mere guesswork, and the logical clues are all there to be read. EQ's writing is here at a peak--the notion that characterization and emotion in his early work were shortchanged is neatly demolished by this tome.Great climax!.