Victorian England. In Yorkshire, several men and horses working on a railway line have been killed—slaughtered, really. The police suspect some kind of wild beast. The government calls upon controversial naturalist Charles Darwin to help with the investigation. A reasonable move, but one that is dictated rather by the least known part of his work: research on what other people would qualify as legendary creatures. It won’t be long before the scientist discovers that he may be right about them after all…

With the beast killed by the soldiers, the strike ends and things seem to return to normal. But there are still some unanswered questions and lingering tensions, especially towards the neo-druids who live in the forest. The death of a young girl triggers a wave of aggression and more deaths. Is anyone controlling the ancient evil in the forests? And why, exactly, is the principled, family-minded Charles Darwin drowning his nights in gin and loose women?

The beast was believed to be dead, and yet... The body has been stolen, its escort massacred. A woman has been killed inside the town. And the neo-Druids have been slaughtered by what they believed to be their god. Even more disturbing, Charles Darwin is revealed to be one of the creatures! The naturalist can no longer deny his dual nature as he struggles with the terrifying question: Could he be the murderous beast that committed the latest murders?