Well-written crime fiction offers the reader more than just engaging characters and a suspenseful plot. High-quality mystery novels also offer the reader an intellectual challenge. Sometimes that challenge is figuring out who, among the many suspects, killed the victim. Many police procedurals present that kind of challenge. The police look for evidence that leads them to the murderer, and the reader’s challenge is to put the clues together before the police do. Another kind of challenge, though, is figuring out how a crime could have been committed. There are several variations on what’s sometimes called the “locked room” motif, and they provide both the sleuth and the reader with a fascinating kind of challenge. How, exactly, could the murder have been committed? Since all of the suspects (if there are any) are accounted for, how did one of them manage the crime?
Sometimes, the victim appears to have been alone, sometimes even literally, in a locked room, when the crime is committed. That’s what happens in Agatha Christie’s Dead Man’s Mirror, a short story that appears in her Murder in the Mews collection. Sir Gervase Chevenix-Gore, an eccentric and very family-proud patriarch, is afraid that someone in his family may be cheating him. He summons Hercule Poirot to his family home for the week-end to find out if his suspicions are correct. On the night Poirot arrives, Sir Gervase is found in his study, the apparent victim of suicide. The study is locked, and the key to the door is found in Sir Gervase’s pocket, so the murderer couldn’t have used the door. The French windows that give on the garden are also locked, so the murderer couldn’t have used the window, either. Chevenix-Gore’s family and friends agree, too, that while it’s highly unlikely, given Sir Gervase’s high opinion of himself, that he would have committed suicide, he was also slightly mad, so everyone believes that Sir Gervase has committed suicide. Two clues, though, lead Poirot to the conclusion that Sir Gervase was murdered.
Ellery Queen’s The King is Dead has a similar “locked room” motif. In that novel, Queen and his father, Inspector Richard Queen, are brought to Bendigo Island, the private property of munitions tycoon “King” Bendigo. Bendigo’s received threatening letters, and he wants the Queens to find out who’s been sending them. One night, Bendigo is shot while he and his wife, Karla, are alone in his hermetically-sealed private office. The room is locked, and a thorough search of both it and the two Bendigos yields no sign of the gun. Moreover, Karla claims that her husband didn’t shoot himself, and the evidence shows that he didn’t. There’s no gunpowder on Karla’s hands or clothes, so she couldn’t have fired the gun, either. Bendigo’s brother Judah had threatened his brother’s life, and actually fired a gun at the same moment that Bendigo was shot. However, Judah was with Queen in another room the entire evening, including the time of the murder, so Queen knows that he didn’t enter his brother’s office. As if that weren’t enough, Judah’s gun had no bullets in it. This intellectual puzzle is almost as interesting as the truth behind why Bendigo was threatened and shot.
Edward D. Hoch’s short story The Oblong Room is another classic example of a locked-room mystery. Again, this story features a victim found within a room that is literally locked up. In that story, Captain Leopold, a Connecticut police chief, is called to the local university campus, where the body of Ralph Rollings has been found with stab wounds. His roommate, Tom McBern, is found in the room, too, and has apparently been there with the body for two days. Captain Leopold tries to unravel the mystery behind McBern’s odd behavior, but at first, nobody’s talking, including a girl they both liked, and friends of both young men. When Leopold finally unravels this “locked-room” mystery, the motive for the murder, and the story behind it, provide the real surprise.
Shelly Reuben’s Spent Matches is another interesting example of a “locked room” or impossible mystery. This novel focuses on Zigfield’s Folly, a New York art gallery. Wegman Zigfield, the gallery’s owner, is upset when his son arranges for the gallery to display the work of Sarkin Zahedi, an artist for whom Zigfield has nothing but contempt. One night, five of Zahedi’s pieces go up in flames in the gallery, and arson investigator Wylie Nolan is called in to investigate the crime. What he finds is that the paintings were destroyed, but the frames were left more or less intact. Moreover, despite the fire, the smoke and fire sensors were never activated. To make matters more challenging, the state-of-the-art security system shows that no-one entered the gallery that night. This novel also features two other fire investigations, but this is the one that’s the most challenging for Wylie. He’s got several suspects, including Zigfield, Jiri Hozda, the Zigfield's associate director, and Jiri Hozda, the Zigfield's associate director, and museum assistant Camden Kimcannon. All three have reasons for objecting to Zahedi’s show.
Sometimes, the “locked room” scenario is more figurative than literal. In those cases, there’s a limited number of suspects and the circumstances of the murder make it hard to see how the murder could have been committed without someone seeing. That’s the case in several Agatha Christie novels. I’ll just mention three of them. In Death in the Clouds (AKA Death in the Air), Hercule Poirot is on a flight en route from Paris to London. During the flight, one of his fellow passengers, French moneylender Madame Giselle, is murdered by what turns out to be poisoned thorn. The only possible suspects are the other passengers in the cabin, and none of them was seen aiming a dart at Madame Giselle, nor even approaching her. The method that the killer used, and the way in which Poirot finds out how and by whom the murder was committed are both fascinating.
That’s also true in Christie’s Murder on the Orient Express, in which a wealthy American businessman is murdered while traveling to London on the famous Orient Express train. Because the cars are locked at night, and because the conductors are on twenty-four hour duty, the only suspects are the other people traveling in the same coach as the murdered man. What’s particularly complex about this puzzle is that each of the suspects has an alibi that’s corroborated by at least one other person, and many of the suspects are complete strangers to each other. So at first, it seems that some outsider must have gotten on board the train at one of its stops. However, since the murder occurs while the train is snowbound between stations, that doesn’t seem possible, either. This is one of Christie’s most challenging puzzles, and still one of her most popular works.
There’s a similar challenge in Christie’s And Then There Were None (AKA Ten Little Indians). That novel takes place on Indian Island, a bleak island off the Devon coast. Ten people have been lured to the island through different means. Shortly after they arrive, the guests realize that they’ve been brought to the island for another purpose. When, one by one, the guests are killed, it becomes clear that one of them is a murderer. Since they’re marooned on an island, there are very few places to hide, and it’s very unlikely that an outsider is doing the killing. Figuring out which one of the people on the island is the killer is one of Christie’s most challenging puzzles, and in fact, this story is said to have been Christie’s favorite of her novels.
My own B-Very Flat also takes up the question of how a murder could have been committed. In that novel, violin virtuosa Serena Brinkman dies suddenly of anaphylaxis on the night of a major music competition. Former police detective-turned-professor Joel Williams works with the local police to find out how and why Serena died. What they find is that there are only a few people who could have had the opportunity to poison Serena, and even fewer who could have removed the epinephrine she always carried.
There are, of course, many other "impossible" mysteries; I've only had space to mention a few. What’s your opinion of the “near impossible” or “locked room” scenario? Do you enjoy the intellectual challenge? Or do you find them too implausible?