About this edition: This edition contains a teaser of the first chapter of the next edition (The Mystery of Villa Sineste by Walter Livingston).
About the author: Not much is known about J. C. Lenehan, other than he was a British writer. His series characters are Inspector Kilby and Charlie Ryan. Here is his bibliography.
- Sir Joshua Jordan, victim of theft of a valuable necklace
- Sam Grundy, rough-looking butler to Sir Joshua Jordan
- David Hyde, diamond merchant
- Connie Hyde, his daughter
- Jack Davis, recently fired assistant to David Hyde, engaged to Freda Lowe
- John Lofthouse, witness to murder
- Freda Lowe, witness to murder
- William Ernest Pardoe, a young boy, witness to murder
- Reggie Robinson, a.k.a. "Light-fingered Freddie" Wilson, witness to murder, a pickpocket
- Richard "Dick" Lowe, a potter, uncle of Freda Lowe, amateur detective
- Dr. Victor Peters, who showed up at a convenient moment
- John Smith, the jeweler
- Abie, the Mole, notorious gang leader
- Police Constable George Brent
- Inspector Kilby of Scotland Yard
- Inspector Parker
David Hyde, diamond merchant, is shot in a train compartment while the train passes through a tunnel. (Note that British trains are unlike American trains - there is no central corridor, each separate compartment, seating 8, has its own exterior door). Sharing the compartment at the time: John Lofthouse, Freda Lowe, Reggie Robinson, young student William Ernest Pardoe, his sister, and two collier's wives. As soon as the train stops, Dr. Peters steps out of the crowd in order to treat Hyde, but he is already dead. None of the other seven in the compartment noticed the shot, and the murder weapon is not in the compartment.
Hyde had been returning from a trip to purchase a valuable necklace from Sir Joshua Jordan. However, Jordan claims he was overpowered by Hyde and robbed of the necklace. The necklace is nowhere to be found.
It turns out the late David Hyde's assistant, Jack Davis, had planned to marry Hyde's daughter Connie. David Hyde opposed the idea, fired Davis, and threatened to cut her out of his will if they did marry.
Investigation begins by Constable George Brent, who also becomes enchanted with Freda Lowe. Several others jump in to "investigate": Dick the Potter has his own theory, Jack Davis lurks around in the tunnel, and the student William Ernest Pardoe has a knack for hanging around the rail yard and observing aspects that are overlooked by everyone else. It soon comes to light that "Dr. Peters" was a fake.
As Jack Davis continues to search for "Dr. Peters", he is captured and held prisoner. Sir Joshua Jordan receives a package and winds up dying in a mysterious manner.
The Tunnel Mystery involves a shooting inside a passenger train compartment as the train passes through a tunnel. The other occupants of the compartment are investigated at length. Much time is spent on trying to figure out just what happened. There are two love stories going on at the same time (Jack Davis/Freda Lowe, George Brent/Connie Hyde) and it is a bit difficult keeping them straight. The action progresses until the very end, and when the murderer is revealed it seems a bit like "Murder on the Orient Express" by Agatha Christie (although that didn't come out until 1934). All the various threads get unravelled on the last few pages. All in all, there are way too many people investigating the crime - official and unofficial. One especially good character is William Ernest Pardoe, a schoolboy who was a witness to the crime. He has a knack of hanging around the rail yard and observing things that the pros overlook.