He also performed live with The Dead Reckoners. In January 2015, the second book of "The Reckoners", titled "Firefight", was published. Leibniz built two Stepped Reckoners, one in 1694 and one in 1706. The Reckoners feed on negative emotions, particularly fear. Against the better judgment of the other Reckoners, David agrees to an alliance with him. The unleashing of the Reckoners has had a number of important side effects. Sanderson has also written YA fantasy, including "The Reckoners" series of urban fantasy. Scientific progress rapidly advances as the Reckoners support experimental designs that normally would not work. The Reckoners travel to Atlanta, or what is now called Ildithia. In it, the Reckoners are controlling Newcago, attempting to restore a Human-Governed society.