The second season of 'Mr. Mercedes' will return to AT&T's Audience Network on August 22. The show, based on legendary writer Stephen King’s 2014 book of the same name, follows demented killer Brady Hartsfield, who taunts retired police detective Bill Hodges with a series of lurid letters and emails. Brendan Gleeson, who plays Hodges and Harry Treadaway who portrays Hartsfield, will be returning for season 2, in addition to a majority of the first season's cast. Reports add season 2 of 'Mr. Mercedes' will be inspired by the second book of the series, Finders Keepers.