The Mortal Instruments is a series of six young adult fantasy novels written by American author Cassandra Clare, the last of which was published on May 27, 2014.

It follows Clary Fray, whose chance encounter with a group of elite angelic superhuman beings -- known as Nephilim or Shadowhunters -- leads her to make life-changing discoveries about herself and her family history.

A recurring theme throughout all Shadowhunters Chronicles books is that "all the stories are true" -- and as a result, many creatures popularized in fantasy writing (e.g., vampires, werewolves, faeries, warlocks, etc.)

"[7] School Library Journal said "Though the story is hampered by predictability and overblown writing, Clare continues her talent for mixing hip, modern humor with traditional fantasy, and fans eagerly awaiting the series conclusion should come away more than satisfied.

"[8] A review in the School Library Journal noted that the book contained a variety of narrative flaws including characters that were "sporadically characterized" and whose behavior was predictable.

1 for 9 weeks straight, knocking series such as The Hunger Games and Percy Jackson and The Olympians off the top spot.

[2] Cassandra Clare has written a series of prequels called The Infernal Devices set in the same universe as The Mortal Instruments, but in Victorian London.

[11] The main characters in this series are Will Herondale, Tessa Gray, and Jem Carstairs, who reside in the London Institute.

There is a sequel series to The Infernal Devices called The Last Hours set in the same universe detailing the adventures of the next generation of Shadowhunters almost two decades after the events of Clockwork Princess.

This series has been published over the course of 2013 and 2014 and consists of "What Really Happened in Peru", "The Runaway Queen", "Vampires, Scones, and Edmund Herondale", "The Midnight Heir", "The Rise of the Hotel Dumort", "Saving Raphael Santiago", "The Fall of The Hotel Dumort", "What to Buy the Shadowhunter Who Has Everything (And Who You're Not Officially Dating Anyway)", "The Last Stand of the New York Institute", and "The Course of True Love (and First Dates)".

The books and release dates are: Welcome to Shadowhunter Academy, February 17; The Lost Herondale, March 17; The Whitechapel Fiend, April 21; Nothing but Shadows, May 19; The Evil We Love, June 16; Pale Kings and Princes, July 21; Bitter of Tongue, August 18; The Fiery Trial, September 15; Born to Endless Night, October 20; and Angels Twice Descending, November 17.

[17] In addition, Cassandra Clare and Sarah Rees Brennan edited a side book titled Ghosts of the Shadow Market.

On October 12, 2014, at Mipcom, Constantin confirmed that The Mortal Instruments would return as a television series with Ed Decter as showrunner.