Adelaide tells Houdini and Doyle about her meeting with Benjamin. Houdini wonders if she hallucinated the entire thing. She insists that she didn’t plans to find Benjamin. Houdini wonders if she wants to find him because she’s worried about him or because she doesn’t trust his story.
Houdini, Doyle and Adelaide investigate 47 deaths in one town. Everyone in town literally dropped dead at about 7am, except Reverend Jasper Farley who had fallen asleep in the bell tower while fixing the bell. They also find a 12-year-old girl, Libby Carter, who was being treated at the doctor’s office and is miraculously still alive, despite the doctor and his dog being dead.
They suspect the water supply may be poisoned by the mine and travel to the Native Americans who live further down stream to see if it has affected them. It hasn’t but three more people die upriver. Doyle thinks the entire valley needs to be evacuated.
When Adelaide realizes that the birds didn’t die, she and Doyle figure out that a wave of carbon dioxide gas flowed out of the mine and killed everyone in it’s path and that some of it is still leaking out of different areas of the mine. The reverend was above the gas in the belfry and Libby survived because her illness affected her breathing.
Adelaide finds that a message written in her husband’s copy of Tom Sawyer matches what’s written in a newspaper ad for Warbridge’s Hardware store. They think it might be some sort of a cypher. Adelaide cracks the code and figures out that the anarchist group is going to try to kill King Edward in two days.
Benjamin shows up at Adelaide’s hotel room. He says he’s trying to stop the plot to kill the king. The two end up in bed together but then she wakes, realizing it was all a dream. Houdini also dreams that he captures the mystery woman following him and it turns out to be his mother.
Houdini figures out that the target isn’t the King of England but the President of the United States who will be staying in the King Edward hotel the next day in Buffalo, NY. They run to stop the assassination when Doyle runs into Benjamin and realizes that he is the assassin. Benjamin shoots Doyle but Adelaide shoots and kills him before he can shoot the President.
Houdini, Adelaide, and a recovering Doyle take a ship back to England. On board, Adelaide mourns Benjamin, Doyle begins to write about Sherlock Holmes again and Houdini worries for his sanity when he begins to see his mother.