While we would argue that a series is never truly over - one can always relive the magic with subsequent readings, after all – alas, there are six and only six books in The Mortal Instruments series: City of Bones, City of Ashes, City of Glass, City of Fallen Angels, City of Lost Souls, and City of Heavenly Fire.  Lucky for us, though, the overarching universe, The Shadowhunter Chronicles, has a plethora of other series, books, and short stories, including some with our beloved Mortal Instruments gang.