Hilary Davidson - Poison

The Art of Poisoning


Growing up, I always knew that one day I’d kill someone with poison.

That was partly because I was fascinated by Agatha Christie novels, in which poison often plays a prominent role. Alfred Hitchcock used it to wonderful effect in his films — think of how Ingrid Bergman was poisoned by her husband in Notorious, and of Joan Fontaine wondering if her husband had it in for her in Suspicion. Other films, like Arsenic and Old Lace, represented poisoners as dotty yet sweet characters. I was also an avid reader of history books about the Roman Empire and Renaissance Italy, and poisonings played a major role in both time periods, reshaping the events of the day and, ultimately, history itself.

Poison seemed like such a democratic way to dispatch someone. After all, you don’t need to be strong or have any particular skill with weaponry. The killer could be young or old, healthy or infirm. It seemed almost easy.

It was only when I decided to poison someone that I discovered how fiendishly difficult it actually is. In my first novel, The Damage Done, my main character, travel journalist Lily Moore, is searching for her sister and discovers several bodies along the way. I knew that poison played a role in those deaths, but when I started to examine how different poisons work, I realized I was in trouble. Poisoning a person isn’t necessarily hard, but avoiding the signs of a poisoning is tough. Sure, you can get rid of someone with arsenic, but all a coroner has to do is look at the victim’s hands to know what’s happened. That wasn’t what I wanted at all, so I had to find ways around it (see below).

In my second novel, The Next One to Fall, poison once again plays a major role. The book is set in Peru, and so I wanted to incorporate some uniquely Peruvian substances. While I was visiting the country, I heard about a substance called ayahuasca, which is also known as natural LSD. It’s not poisonous itself, but it can be deadly when mixed with other drugs. It can also lead to terrible accidents if you get someone to take it and then, say, abandon them at a mountaintop city in the Andes. (The Next One to Fall begins with a woman’s mysterious death at Machu Picchu…)

Because of writing these books, and several short stories in which poison plays an important role, I’ve learned a lot about the art of poisoning. Here are some things to keep in mind when writing about it:

1. Poisoners need no physical strength, but they must have nerves of steel.
Shooting or stabbing someone takes a mere moment, whereas poison requires dedication. Many poisons require a certain amount of time to work — often it’s days, but it could be a week or more — and the poisoner must administer several doses of poison. Given that the poisoner normally needs to be in close proximity to his or her victim, this means that the killer has to be able to look into the eyes of their victim, engage them in conversation, perhaps even be affectionate with them — all the while knowing that they’re killing this person.

2. The most common poisons aren’t what you think.
Cyanide, arsenic, and strychnine are some of the poisons readers encounter in fiction. In reality, the most common poison used today is antifreeze (ethylene glycol). It’s sweet, mixes well with some liquids, and is tough to detect unless poisoning is suspected (it damages certain organs and leaves evidence that would be obvious in an autopsy). Otherwise, the death looks quite natural.

3. Smart poisoners work with what they’ve got. 
Importing some exotic poison (and there are several amazing, hard-to-detect ones in South America… but I digress) only leaves a trail for the authorities to follow. After all, the more exotic the poison, the tinier the circle of people who can access it. The clever killer looks for drugs that are already in the victim’s medicine cabinet, and that are not, in prescribed doses, deadly. One of my more inspired killers used Viagra this way (an overdose can cause a heart attack). Also, some prescription drugs do not play well with others. Read medical warning labels to get an idea of what not to do… so that when you’re writing about a poisoner, you know what kind of damage they can cause.

4. Poisons can be used in ways that aren’t deadly.

In The Next One to Fall, there is a character who is on a lot of prescription pills, all of which are legal. When Lily discovers this, she assumes the person is a drug addict or else a total hypochondriac. It takes time to realize that mood-enhancing and –stabilizing drugs can be used to control someone’s actions, and make them do things they wouldn’t normally do.

Writing about poisons has made me expand my definition of what a poison can be. I think that’s true of my readers, too. One reviewer wrote that, after reading The Next One to Fall, he’d never even look at aspirin the same way. I take that as a compliment.



Hilary Davidson won the 2011 Anthony Award for Best First Novel for The Damage Done. The book also earned a Crimespree Award and was a finalist for the Arthur Ellis and Macavity awards. The sequel, The Next One to Fall, a mystery set in Peru, was published by Tor/Forge in February 2012. Hilary’s widely acclaimed short stories have been featured in publications including Ellery Queen Mystery Magazine and Thuglit, as well as in many anthologies. A Toronto-born travel journalist and the author of eighteen nonfiction books, she has lived in New York City since October 2001. Her next novel, Evil in All its Disguises, will be published by Tor/Forge in early 2013.