In Sarah Pinborough’s Mayhem, another savage murderer is butchering women in London at the same time as Jack the Ripper.

Was there one book that inspired Mayhem?

Dan Simmons’s The Terror. I found it gripping and loved the mix of real historical events and people blended with a vaguely supernatural strand. I decided then that I wanted to do something similar—although Mayhem is a much smaller book, and I don’t claim to have come anyway near to matching The Terror’s brilliance. I really wanted to write a book about madness, and how we are all capable of becoming part of a mass hysteria, and how true horror lies inside ourselves.

How did you decide to use the Torso murders?

The Thames Torso murders almost fell into my lap. After deciding to use a real historical crime as the focus for the book, I went to Google and searched for unsolved murders in Victorian London, and they basically popped out at me about halfway down the first results page. As soon as I started looking a bit deeper and realized they were taking place at the same time as the Ripper murders, and that one torso was found in the basement of the New Scotland Yard building, I was hooked.

What interested you about them?

I’m one of those gruesome people who finds murder interesting (from a distance), but these killings had several elements that really interested me. First, none of the victims’ heads were ever found, and only one victim was ever identified. I loved—if that’s an appropriate word—that the killer was so clinical. No one knows where he killed his victims or why, only that he chopped them up and threw their wrapped body parts into the Thames, with the exception of the torso, arm, and leg found in the Scotland Yard vault and another limb found in Battersea. He also removed breasts and various organs, some of which were never found. It’s likely his first victim was in Paris, where a dismembered body was found on the steps of a church, and then he traveled to London. There’s a very Hannibal Lector feel to this killer. He didn’t do it for show or attention. There’s a sense it was entirely for his own gratification, and he was very careful not to get caught.

Did they differ from the Ripper’s crimes?

There is a wonderful contrast between the two killers—one all frenzy and impulse, and the other clinical, cold, and calculated, and the idea that they were both stalking the streets of London at the same time is a gift to a novelist.