Adam Robitel wrote the spec screenplay, which is based on the true story of the Bender's. This family ran a small hotel in the Kansas prairie in 1873, and brutally murdered 20 of their guests. The killers were never punished for their crimes. Here's what Guillermo del Toro had to say about this unique project.
"It is a beautiful and brutal yet poetic story, based on a very famous case. If you consider America back then, it was a great transition to modernity, but on the prairie, these were huge landscapes where people traveled and days and weeks on end would pass without communication. So nothing happens, then there is this brutal murder, and then it's back to pastoral peace and quiet. That rhythm was very attractive to me. The time was so lax back then that the sheriff would show up and say, 'What is that odor coming through the vent that smells like decomposing flesh?' The Benders said they didn't know. And the sheriff said, 'Would you mind if I take a look...tomorrow?' Nobody was in a hurry, and that is a big reason why they got away with it."
Guillermo del Toro will work on polishing the script with Adam Robitel, a protege of Bryan Singer, but he will not direct.