For instance, in Agatha Christie’s Appointment With Death, Hercule Poirot investigates the murder of Mrs. Boynton, a wealthy American widow who’s tyrannized the members of her family all of their lives. She is a malicious mental sadist who assumes that everyone in the family will be completely under her control. Her expectation leaves her vulnerable, though, as we find out when the family takes a trip through the Middle East. Because Mrs. Boynton expects to dominate everyone, she isn’t aware of how much danger she is in. Then, one afternoon during an excursion to the ancient city of Petra, Mrs. Boynton suddenly dies. At first, her death appears to be caused by heart failure. But Colonel Carbury, who’s in charge of the investigation, isn’t sure. So he asks Poirot to help with the case. Poirot finds that the danger to Mrs. Boynton came from a source she would never have expected.
There’s another case of assumptions making one vulnerable in Minette Walters’ The Breaker. When the body of thirty-one-year-old Kate Sumner is found on a beach near Chapman’s Pool, DC Nick Ingram works with the Devon and Hampshire constabularies to find out how and why she was killed. As the investigators slowly learn about Kate’s life, they find that she had a very dangerous assumption that she was in control of all of her relationships. In fact, Kate’s relationships and the way she dealt with them are a key factor in this story. That expectation that she would be “in charge” made her vulnerable to a killer who was much more dangerous than it appeared on the surface.
One of the reasons that well-written financial, medical and legal thrillers can be so engaging is that they examine what happens when we can’t trust those people that many of us have been brought up to assume we can trust. When we put our health in the hands of a doctor, or our legal matters in the hands of an attorney, or our financial matters in the hands of a consultant, we hope – even expect – not to be exploited. We almost have to assume that the doctor will help heal us, the attorney will represent our interests and the financial advisor will not steal our money. There are far too many of these kinds of novels for me to list them all. A quick review of books by the likes of Michael Palmer, Philip Margolin or Emma Lathen is enough to remind you of the sense of betrayal that happens when people find they cannot trust those whom they’ve expected to be trustworthy. That shock and sense of dissonance often adds a great deal to the tension in this kind of thriller.
Of course, it’s not just victims whose expectations and assumptions can be violated. That happens to sleuths, too, and it’s one reason for which wise sleuths don’t have too many assumptions about who committed a crime. Sleuths who have too many preconceived notions and expectations are likely to miss important clues that don’t fit their assumptions.
For instance, in Dorothy Sayers’ Strong Poison, mystery novelist Harriet Vane is on trial for the poisoning murder of her former lover, Philip Boyes. Almost everyone believes that Harriet is guilty, because the only thing that Boyes consumed on the night of his death that no-one else had was a cup of coffee that Harriet gave him. So it is assumed that Boyes could not have been poisoned in any other way. Lord Peter Wimsey, who attends the trial, becomes smitten with Harriet and determines to clear her name. He and several of his friends work together to find out what really happened when Boyes died. What they find is that the assumption that Boyes could only have been poisoned by the coffee almost cost Harriet Vane her life. In the end, Wimsey is able to show that that assumption was wrong.
In Michael Connelly’s The Concrete Blonde, Harry Bosch is the subject of a civil trial for the shooting of Norman Church. Bosch believed that Church was a serial killer known as “The Dollmaker.” Church’s family brings a wrongful death suit against Bosch, claiming that Church was not the murderer. Bosch, though, is convinced that he was right. Then, another killing occurs that bears all of the hallmarks of “The Dollmaker.” Since Church is dead, he can’t have committed this most recent killing, so Bosch has to re-think his assumptions. He has to do the same thing in Echo Park, when a convicted serial killer named Raynard Waits offers to trade information about earlier killings in exchange for avoiding the death penalty in two new murders. One of those older cases is a case Bosch worked on - the murder of Marie Gesto, who walked out of a Hollywood supermarket one day and never made it home. Bosch couldn’t make an arrest in the Gesto case because he missed an important piece of evidence. He had different assumptions and expectations about that case that led him to another suspect, but he never had the hard evidence he needed to make an arrest. When Bosch finds out about Waits, he has to completely change his view of the Gesto case.
Carole Sutton’s The Ferryman also shows what happens when sleuths rely too much on assumptions and expectations. In that novel, Steve Pengelly moves to the Isle of Guernsey, where he hopes to start a new life. With help from a new acquaintance, Angela Dupont, he buys a beautiful thirty-food sailboat and is soon established in his new place. He begins an affair with Angela, but that affair ends with a violent quarrel when Steve finds out that Angela has been using him until she can find a wealthier, better-situated “catch.” Shortly after their breakup, Angela mysteriously disappears. DI Alec Grmstone bases his investigation on the expectation that people are usually murdered by someone they know, even love. So he focuses on Steve, and the evidence he collects looks suspicious. For instance, there were traces of blood found on Steve’s beloved boat. On the weight of his assumptions, Grimstone prosecutes the case and Steve Pengelly is tried, convicted and jailed. Two years later, he’s still in jail when the body of Angela Dupont washes up at Cornwall’s Fal Estuary. Everyone’s assumptions are turned upside down when it turns out that she has only been dead for a short time. She was killed while Pengelly was in prison, so he could not be guilty. Now, Grimstone has to start all over again on the case.
Of course, sleuths can also use assumptions to their benefit. For example, Dorothy Gilman’s Mrs. Pollifax doesn’t seem to be the type of person you’d fear as an international spy. And in several novels, she uses that to her advantage. She appears to be a nice, non-threatening elderly lady. And yet, she’s quite quick-witted and well able to use the assumptions people make about her and the expectations they have for her against them. The same is true of Agatha Christie’s Miss Marple. People assume that because she’s elderly and a woman, that she’s not to be taken seriously. And Miss Marple cultivates that “soft” non-threatening exterior when it suits her. But criminals make those assumptions to their detriment…
Assumptions and expectations can add some predictability and order to our worlds. But they can also blind us, so that we can be dismayed or worse it they are violated. What do you think? Which novels have you enjoyed where assumptions prove to be someone’s undoing?