A Feast of Poisons (Kathryn Swinbrooke 7)

The village of Walmer near Canterbury is a small, claustrophobic place where everyone knows everyone else's business. Everyone knows the blacksmith, Elias, liked to drink and liked the ladies. Everyone knows his wife, Isabella, had been spotted many a time entering the woods with men other than her husband. And everyone knows the couple fought, sometimes violently. But could they have independently, on the same day, murdered each other with two entirely different poisons? The village's medicine woman, Mother Croul, doesn't think so.
And neither does Kathryn Swinbrooke, Physician of Canterbury, who is in town with her new husband, Colum Murtagh. Kathryn and Colum are visiting on state business: Lord Henry Beauchamp is to receive the shadowy emissaries of Louis XI of France, on behalf of his own master, Edward of York. It is a tense time for the kingdom; everything hinges on the meeting between Lord Henry and the French agents.
But now, as a murderer stalks the land, only Kathryn Swinbrooke can cut through the web of deceit that arrives with the Spider King's minions.