The disturbance, of course, comes from "H.H. Holmes," the serial killer who ran a small hotel near the Jackson Park site of the fair and who, um, killed people. The book is designed to try to get you into his head, as well as into what was disturbing people in this era: an economic depression (almost a great depression long before The Great Depression) that threatened to scuttle the fair and much other development before it could properly start, and the slowly-coalescing concept of the psychopath. It'd be decades (not until the 1940s, I think?) that the term "serial killer" would be coined, but in the late 19th century our ancestors were reading of Jack the Ripper and his horrors. We didn't have enough names for it, but we were learning the signs. We were horrified and fascinated. Psychopaths like "Holmes" were mentally taking notes.
The great vast majority of us do not have psychopaths in our lives. Thank everything. But the book was pinging my sociopath radar. Quite a lot of us do have sociopaths to deal with. I wish we didn't, because I know from enough experience what sociopaths are like. Some people formally in my life? Ain't there no more, as they were sociopathic and I felt burned by it. Maybe I'm better at self-preservation now. I don't know. Maybe I'm less likely to give people the benefit of the doubt now. About that, I also don't know. I mainly know that sinking feeling of thinking of someone and wanting to tell them you're not really meaning what you're saying, or really feeling what you're presenting as feelings. And with the sociopaths I've known, calling them out about it seemed pointless: they'd twist and repurpose it into being something wrong with the world, not with them. I've seen that happen. I can't correct that for all the sociopaths: I just have to do my best not to get in their way, and -- in an effort to NOT BECOME LIKE THEM -- point out to people when someone they know might be a sociopath.
I leave you with the wisdom of Justified's Raylan Givens: "You ever hear of the saying 'you run into an asshole in the morning, you ran into an asshole; you run into assholes all day, you're the asshole.'"
Don't be the asshole.