The series follows Clary Fray, Jace Herondale, Simon Lewis, Isabelle Lightwood, Alec Lightwood and other Downworlders and Shadowhunters in the New York Institute. Seemingly normal at first, Clary soon gets sucked into the world of Nephilim and other creatures when she finds out that she is a Shadowhunter.
- City of Bones
- City of Ashes
- City of Glass
- City of Fallen Angels
- City of Lost Souls
- City of Heavenly Fire
- City of Bones was narrated by Ari Graynor and, in a new version, by Mae Whitman.
- City of Ashes and City of Glass were narrated by Natalie Moore.
- City of Fallen Angels was narrated by Ed Westwick and Molly C. Quinn.
- City of Lost Souls was narrated by Molly C. Quinn.
- City of Heavenly Fire was narrated by Jason Dohring and Sophie Turner.
The first of the series, City of Bones, was adapted onto the big screen, The Mortal Instruments: City of Bones, produced and distributed by Constantin Film. Initial reports claimed plans for a film trilogy based on the first three books; however, due to the film not meeting the expected success, the sequel's production was constantly delayed, until it was ultimately scrapped.
On October 12, 2014, it was announced that The Mortal Instruments would instead be relaunched by Constantin Film as a television series. The show premiered on January 12, 2016 and concluded on May 6, 2019; it consisted of three seasons with a total of 55 episodes.
To coincide with the movie release, a graphic novel also based on the first book was released in 2013 but was discontinued after seven issues. In 2015, it was announced that the graphic novel rights to the series had been reclaimed and instead be adapted into a graphic novel series by Cassandra Jean with two installments per book.
- The series was initially meant to only be a trilogy, ending with City of Glass.
- This trilogy had been meant to be followed by a spin-off graphic novel focusing on Simon and what happened to him after the events of City of Glass; as well as wrapping up the loose ends from the final chapter.
- The series title refers to the three Mortal Instruments which were featured and crucial to the events in the series.
- The series was inspired by Paradise Lost and The Inferno.
- The idea from the series came from sets of footprints on the ceiling of a tattoo shop that "looked like some fabulous supernatural battle had been fought there by beings who'd left their footprints behind."
- The series name was taken from Shakespeare's Julius Caesar. Certain lines were used as an epigraph of the first book in the series, City of Bones.
- The US/Canada paperback book covers of The Mortal Instruments were updated (repackaged) and officially replaced with new ones with a more modern look, released on September 1, 2015 by Simon & Schuster. The covers were revealed on May 12, 2015 on the various social media accounts of Shadowhunters: The Mortal Instruments. The hardbound covers will remain the same.
- Simon & Schuster also has further plans to do "adult covers" of the series.
- The UK/Australia/NZ/Ireland publisher, Walker Books, also released new covers in July 2015, with the illustrations done by artist Mila Furstova. Unlike the US repackages, the new covers will simply be alternatives instead of replacements for the originals.
- Cassandra Clare on her Site
- 1. Where did you get the idea for the Mortal Instruments books? — About the Books, Cassandra Clare FAQ