London 1884. A culprit is on the run after a fatal poisoning in Bermondsey. It seems like a simple case for Penny Green to report on, until a series of macabre photographs is discovered.

As the poisonings continue, Scotland Yard is convinced they have their suspect. It's not long before they're outwitted and no one is safe. Penny and Inspector James Blakely must avoid the red herrings and track down the manipulative poisoner.

But could there be more than one?