The working title of Furies of Calderon was Shepherd Boy's Fury, but Jim Butcher's marketing people made him change it.
The series was started by a bet: another aspiring author bet Jim Butcher that he couldn't write a good book based on a bad idea. Jim not only said he could, but allow the author to choose two bad ideas to base the series on. The other author chose Pokémon and the lost 9th Roman legion.
