"The Affair of the Poisons" tells the story of François Ravisson, an archivist hired to catalog a cache of documents dating from the reign of Louis XIV, which had been relegated to a storeroom and forgotten about since the Sun King's reign. What he discovers is an infamous and secret scandal; Louis may have built a glittering palace to rival any in Europe, but underneath the gilding lay a dark, criminal world where human life was up for sale, and cheap.

The women of 17th century France may have dressed like fairy princesses, but their reality was one of little agency, especially if they were unlucky enough to be married off to the wrong man. Fortunately for them, the Paris underworld was brimming with a cartel of women supplying "inheritance powders." But what happens when the rash of poisonings and dead husbands reaches straight into the heart of Versailles?

And in François' world of the nascent Second Republic, what will happen when France elects the popular, autocratic nephew of Napoleon to be its first President? Will there be time to finish uncovering the scandal before the new administration cuts off his access? Will the story of what happened to the dozens of women involved be lost to history again?