For instance, in Agatha Christie’s The ABC Murders, sweetshop owner Alice Ascher becomes a “canary in a coal mine” when she is murdered very late one afternoon while she’s working in her shop. At first, her husband Franz is suspected, and that’s logical. The two were on bad terms and he’s even threatened her life. The only reason he’s not immediately arrested and tried for the crime is that Hercule Poirot has received a cryptic warning of the murder – a warning Ascher would not have sent. Poirot is aware of the significance of that warning, and you could even say he understands that Ascher’s death is a warning. He says to Captain Hastings,
“This is the beginning.”
His words are prophetic, as he and Hastings are soon involved in the investigation of what looks very much like the work of a serial killer. It’s not until three more deaths occur that Poirot puts all the pieces together and is able to stop the murderer.
In Christie’s Hickory Dickory Dock (AKA Hickory Dickory Death), a resident of a hostel for students becomes the “canary in a coal mine.” Several items have been taken from residents of the hostel, and Mrs. Hubbarad, who manages the hostel, is concerned about them. She tells her sister, Felicity Lemon, about the thefts, and Miss Lemon asks her employer, Hercule Poirot, to investigate. To Poirot, the items stolen are interesting in that all of them are unusual (e.g. one item is a set of lightbulbs; another is one of a pair of shoes). Two days after Poirot’s first visit to the hostel, Celia Austin, a resident there, dies of what looks at first to be suicide. Soon enough, it’s clear that she was murdered. Now, Poirot works with Inspector Sharpe and his team to find out what’s behind the thefts and the murder. In the end, Poirot discovers that Celia’s death was only the proverbial “tip of the iceberg” of what’s been going on at the hostel.
In Ellery Queen’s The Origin of Evil, we meet nineteen-year-old Lauren Hill, whose father, successful businessman Leander Hill, has recently died. Lauren believes that his death was not an accident, and asks Ellery Queen, who’s staying at a house in the area, to investigate. Queen’s unwilling at first, but soon, he finds the puzzle of Hill’s death intriguing. Before he died, Leander Hill received several odd “gifts.” One of them was the macabre “present” of a dead dog. His business partner Roger Priam also received several cryptic packages. That dog turns out to be the “canary in a coal mine,” as we discover when Queen begins to investigate. What Queen finds is that the packages are warnings of what’s to come, and that Leander Hill’s death is related to his past.
In Emma Lathan’s Murder to Go, several customers of Chicken Tonight, a fast-food franchising company, become “canaries in a coal mine” when they fall ill after eating one of the company’s new recipes. One customer actually dies of poisoning. Lathen’s sleuth John Putnam Thatcher, vice-president of the Sloan Guaranty Bank, gets involved in this case because his bank is planning to broker a merger between Chicken Tonight and Southeastern Insurance. Thatcher discovers that several people involved in the merger may have had reasons for not wanting it to go through. When it looks as though the poisonings may scuttle the merger, it becomes clear that much more is going on than a simple case of a disastrous accident at a restaurant.
Many of Robin Cook’s medical thrillers involve his sleuth(s) investigating a mysterious set of deaths or illnesses. Many of those involve people you could consider “canaries in a coal mine.” One of the clearest examples of this is in one of Cook’s early novels, Fever. Dr. Charles Martel is a brilliant cancer researcher is pulled from the study he’s been doing for the Weinburger Institute to work on a new treatment drug called Canceran. Martel isn’t convinced of the drug’s efficacy, but the Institute is depending on Canceran to put it on solid financial footing. Martel determines to continue his own research in secret. That turns out to be a wise idea when Martel discovers that his fourteen-year-old daughter Michelle has been diagnosed with acute myeloblastic leukemia. In his search for answers about her leukemia, Martel discovers that Michelle is a “canary in a coal mine.” A local company has been dumping highly toxic waste into a river not far from the Martel home, and Michelle’s leukemia can be traced directly to that toxic waste. Now, Martel is up against not only his daughter’s illness, but also a very large, well-funded and determined company.
Michael Crichton’s Airframe has another interesting example of “canaries in a coal mine.” In that novel, TransPacific Airways Flight 545 is en route from Hong Kong to Denver when a terrible mishap causes an emergency landing at Los Angeles’ LAX airport. Many of the passengers are injured, some severely. Three are dead. Casey Singleton, a vice-president for Norton Aircraft, learns that those passengers are “canaries in a coal mine” when she investigates the disaster. Since Singleton’s company manufactured the plane, her first step is to look into the plane’s construction as well as manufacturing procedures. With help from veteran Norton employee Amos Peters, Singleton discovers that much more was going on than just a tragic manufacturing error.
Donna Leon’s Through A Glass, Darkly also includes a character whom you might call a “canary in a coal mine.” In that novel, Giorgio Tassini works nights at Giovanni De Cal’s glass-blowing factory. He’s upset because he believes that De Cal’s and other similar factories are illegally dumping toxic waste into the water supply. In fact, he believes that his own daughter has been affected by this waste. She’s got multiple special needs that Tassini blames on the illegal dumping. His belief that she’s a “canary in a coal mine” spurs him on to protesting the factories – and causes his murder. Commissario Guido Brunetti and Ispettore Lorenzo Vianello investigate Tassini’s death. They find that his murder is related to what Tassini has found about the glass-blowing industry’s practices.
The “canary in a coal mine” can be an effective strategy to build tension and suspense, add interest and get the sleuth involved in an investigation. Which novels have you enjoyed that use this plot point?
*NOTE: The title of this post is a line from The Police's Canary in a Coal Mine