American TV series, airing on the FX Network , about the professional and personal lives of New York City firefighters after the trauma of the September 11 . Contents 1 Season 1 1.1 Guts [1.01] 1.2 Gay [1.02] 1.3 Kansas [1.03] 1.4 DNA [1.04] 1.5 Orphans [1.05] 1.6 Revenge [1.06] 1.7 Butterfly