A Study in Viridian follows Sherlock Holmes and Dr. Joan Watson into the heart of modern-day Manhattan, where an unexplained poisoning sets them on the trail of a mystery hidden in chemistry. As baffling cases emerge and the clues grow more elusive, Holmes discovers that the greatest challenge isn't finding the poison: it's proving it was ever there. Blending authentic toxicology with classic deduction, this original audio drama asks one simple question: what if Sherlock Holmes' greatest cases began with a molecule?