We see a clear example of this in Arthur Conan Doyle’s The Hound of the Baskervilles. Sir Charles Baskerville is found dead one morning in the park of his manor, apparently of a heart attack. However, Baskerville’s friend, Dr. Mortimer, thinks that Baskerville has fallen prey to a family curse. According to the local legend, Baskervilles’ ancestor, Sir Hugo Baskerville, had sold himself to the Powers of Evil in return for a young woman with whom he’d become infatuated. Now, the Baskerville family is haunted by a demon who takes the form of a large hound with “blazing eyes and dripping jaw.” Mortimer is convinced that this evil hound exists, and he fears for the safety of the next Baskerville heir, Sir Henry, who’s coming from Canada to assume the title. So he asks Sherlock Holmes to investigate the case. Holmes agrees and he and Watson travel to Baskerville Hall. When they arrive, they begin to look into the case and in the end, they find out that everyone’s eyes have been deceived. The real reason for Sir Charles’ death has nothing to do with a family curse.
There are several Agatha Christie novels in which characters are victims, if you will, of the tricks their minds play on them. For example, in Hercule Poirot’s Christmas (AKA A Holiday for Murder and Murder for Christmas), we meet Tressilian, the aging butler to the Lee family. When his master, old Simeon Lee, invites the members of his family to spend Christmas at the family home, they’re very reluctant to accept the invitation, because Lee is an unpleasant tyrant. No-one dares refuse, though, because he’s also rich. When the family begins to gather, Tressilian has the distressing feeling that everything he’s doing has happened before and it troubles him. He also feels that his eyes are playing tricks on him. Then, on Christmas Eve, Simeon Lee is brutally murdered. Hercule Poirot is spending Christmas with a friend nearby, so he’s called in to investigate. In the end, Poirot finds that Tressilian’s sense of being deceived by his own eyes is a very important clue to Lee’s murder.
In Christie’s Third Girl, there’s an even more chilling example of being deceived by one’s own senses. In that novel, Norma Restarick, a troubled young woman, goes to visit Poirot because she thinks she may have committed a murder. When she meets Poirot, she decides Poirot is too old, and won’t even give him her real name. It isn’t long, though, before Poirot is able (with the help of his friend, Ariadne Oliver) to find out who the young woman is and begin to investigate her story. He and Oliver find out that Norma Restarick has been very much the victim of her own senses, and has been deliberately (and quite cold-bloodedly) led to believe she’s a murderess.
A similar thing happens to Howard Van Horn in Ellery Queen’s Ten Days Wonder. Van Horn’s been having a frightening series of blackouts; he wakes up after one of them covered in blood and with no memory of what’s happened. Terrified that he might have done something horrible, Van Horn seeks out his old college friend, Ellery Queen. Queen agrees to help Van Horn find out what might have happened. Their search for answers leads them to Van Horn’s hometown of Wrightsville, a small New England town. While they’re in Wrightsville, Queen and Van Horn stay with Van Horn’s father, wealthy Diedrich Van Horn, and his much-younger wife, Sally. One night, Howard has another blackout, during which Sally is murdered. Howard is convinced he murdered Sally, although he doesn’t remember doing it. Queen isn’t convinced, though, and looks into the case. Unfortunately, the more evidence he collects, the more it all seems to point to Van Horn. It’s not until the very end of the novel that Queen realizes that Howard has been tricked into believing himself guilty.
In Caroline Graham’s A Place of Safety, Charlie Leathers sees what he thinks is a murder. Late one night, he’s out walking with his dog when he sees the local curate’s wife, Ann Lawrence, struggling on a bridge with Carlotta Ryan, a troubled teenager who’s been living with the Lawrences. Leathers sees the young girl tumble into the water and, to all intents and purposes, it looks as though she’s drowned. All is not as it seems though. Soon after Carlotta Ryan’s disappearance, Leathers himself is killed and Inspector Tom Barnaby and Sergeant Gavin Troy are called in to investigate Leathers’ murder. What they find is that Charlie Leathers’ eyes deceived him, as the saying goes, and that there’s more to Carlotta Ryan’s disappearance than a simple struggle gone terribly wrong.
There are a few examples of being deceived by what one sees in Alexander McCall Smith’s No. 1 Ladies’ Detective Agency series. For example, in the first novel of the series, Mma. Precious Ramotswe is approached by an old friend, Dr. Maketsi. Maketsi is worried about Dr. Komoti, one of the doctors who works for him at the local hospital. At times, Dr. Komoti seems to be an extremely competent doctor who can perform even complicated procedures. At other times, he doesn’t seem able to do even basic procedures such as stitching up wounds. Maketsi believes that Dr. Komoti is using drugs and asks Mma. Ramostwe to help him find out if that’s true. Mma. Ramotswe agrees, and begins to look into the matter. What she finds is that the hospital staff has been tricked into believing what they see. As it turns out, the truth is quite different from what Dr. Maketsi thinks.
That’s also true in Morality for Beautiful Girls. One of the cases that Mma. Ramotswe takes in that novel is the case of a Government Man who is convinced that his new sister-in-law is trying to poison his younger brother, Mogadi. He doesn’t trust his brother’s wife, so he asks Mma. Ramotswe to go to the family farm and find out whether his brother is really in danger. Mma. Ramotswe agrees, and is invited to the farm. When she gets there, the family is served some food, and that night, everyone gets sick, including Mma. Ramotswe. So it seems that the Government Man is right about his sister-in-law. However, Mma. Rramotswe isn’t convinced. She’s heard from others that his sister-in-law is a good woman who loves her husband, and she doesn’t see any motive for the poisoning. In an interesting twist, it turns out that the Government Man thinks his brother’s being poisoned because that’s what he wants to believe. His mind has deceived him. Once Mma. Ramotswe finds out the real reason for everyone getting sick, and the Government Man’s reasons for his beliefs, she’s able to help settle the family dispute.
In real life and in crime fiction, it’s sometimes all too easy to believe what we want to believe, and see what we want to see and it’s only later that we realize how we’ve been deceived. I’ve only mentioned a few examples here; space doesn’t permit me to list all of them. What do you think of novels where this is a theme? Which ones have you enjoyed?