Since leaving "The Simpsons", Swartzwelder has taken up writing absurdist novels, beginning with the 2004 publication of science fiction detective story "The Time Machine Did It" starring private investigator Frank Burly. The next year he published "Double Wonderful", a Western, before returning to the Burly character for "How I Conquered Your Planet" in 2006, "The Exploding Detective" in 2007, "Dead Men Scare Me Stupid" in 2008, "Earth vs. Everybody" in 2009, "The Last Detective Alive" in 2010, "The Fifty Foot Detective" in 2011, and "The Million Dollar Policeman" in 2012. In 2014, a children's book written in the late 1970s by Swartzwelder and illustrated by David Schutten was published by Green House Books. Swartzwelder self-publishes his books.