Kudos indeed to the folks at Bloomsbury Sigma for thinking of The Well-read Naturalist when rolling out the advance notices for Kathryn Harkup’s new book A is for Arsenic: The Poisons of Agatha Christie. After all, what if not ingenious distillations of the natural world – as well as important clues to the identity of the culprit – were the classic poisons featured in Dame Agatha’s famous mystery novels?