As the 19th century draws to a close, war is in the air, and influenza is sweeping the globe. Montmorency and his companion, Lord George Fox-Selwyn, are offered an attractive job. Can they trace some rare specimens stolen from the collection of a reclusive naturalist?

Their search leads them to Italy - but what they thought would be a holiday from the world of international intrigue instead leads the pair to discover a web of anarchist conspirators, intent on spreading terror and death across Europe.

It’s been 20 years since Montmorency crawled out of a sewer and started his new life as a gentleman. But could his alter-ego Scarper re-emerge in the hope of influencing a younger generation - in particular, George’s nephew, Frank? And can he be of help as they delve into the violent political underworld to thwart a plot that threatens hundreds of lives …?