December 1882. Attending the opening of the new Natural History Museum, Pall Mall Gazette reporter Alec Lonsdale and his colleague Hulda Friederichs are shocked to discover a body in the basement, hacked to death. Suspicion immediately falls on a trio of cannibals, brought over from the Congo as museum exhibits, who have disappeared without trace.
Alec however has his doubts – especially when he discovers that three other influential London men have been similarly murdered. When he and Hulda discover a letter in the victim’s home warning of a catastrophic event planned for Christmas Eve, the pair find themselves in a race against time to discover who exactly the Watchers are and what it is they want …