Zoe let out a long exhale. “There are only about a hundred common drugs and poisons that are routinely tested for at autopsy. And there are literally thousands of things that can cause death. It’s intuition that sets me on the hunt for this something else. Many poisons mimic the effects of natural symptoms or a medication overdose. For example, strychnine poisoning and a tetanus infection mimic each other. The signs of oleander poisoning replicate the effect of a digitalis overdose, a drug that helps the heart beat stronger. So, I’ll look for poisons that could have imitated her possible causes of death. You said she was missing for several days before she was discovered, right?”

“Yes, she was alive for five days before her death.”

“My next guess is that she was given something that took that amount of time to do its job. I’ll start with drugs or poisons that don’t take effect immediately.”

Val narrowed her eyes. “Do you think she was held somewhere purposely in order to poison her?”

“Possibly. Val, the trick with poisons is to make sure they do their job slowly—that irreversible damage is done which eventually leads to death after several days, while the drug itself dissipates from the body during the process because the person is still alive to metabolize it. An expert poisoner can avoid detection every time if they just remain patient. As I said, most poisons replicate natural symptoms and ailments. They get confused for these. And if you’ve administered your poison the right way, over the right time. Bingo! Dead person. Looks natural. No poisons can be detected since the body eliminated them, and you go free. It’s so perfect it’s beautiful.”

“Are there common poisons that people use?”

“Yes, and some become en vogue,” Zoe scoffed. “Honestly, I can spot those a mile away. Ethylene glycol, or antifreeze, is the number-one poison in the US right now. Buying it doesn’t raise suspicions, especially in winter. Plus, it has a sweet taste. You can put it into anything that’s already sweet and your victim can’t taste it. Let me tell you that it’s a nasty, nasty way to go. It forms calcium oxalate crystals which are pretty sharp. Once those crystals go through your system and arrive at your kidneys, they shred them apart. But this is all common knowledge amongst toxicologists. No one who knows what they’re doing, does this kind of basic 101 poisoning. As I’ve said, a skilled poisoner knows how to do it right, in the right amounts and is patient during all of it. That’s the triumvirate of skills of a master poisoner.”

“Remind me never to make you angry!” Val laughed and wheeled a few feet back from Zoe. “I need to keep a safe distance.”

“Hey, we all have our strengths. I have to at least claim something someone can inscribe on my gravestone.”