A race of humans who possess angel blood, the Nephilim or Shadowhunters, is organized to patrol the Shadow World and prevent demons as well as Downworlders, including warlocks, faeries, werewolves, and vampires, from attacking the mundanes.
Beginning in 1878, in London, the trilogy follows Tessa Gray, an American teenaged girl who arrives in England following her brother's invitation to move in together.
But she is quickly thrust into the Shadow World when she is kidnapped by two warlocks known as the Dark Sisters, who claimed Tessa for her ability to change her appearance, a power even she had not yet known she had possessed.
Upon learning that she is at the center of an evil plot raised by someone known only as "the Magister," Tessa begins to work with the Shadowhunters of London to discover the truth of her past, and in so doing meet the two great loves of her life: Will Herondale and Jem Carstairs.
The series is mainly set in the year 2007 and revolves around Clary Fairchild, a fifteen-year-old who witnesses a murder invisible to everyone but herself, committed by a group of tattooed teenagers known as Shadowhunters.
As Clary discovers her own supernatural abilities, she learns of her role among the Nephilim, human-angel hybrids tasked with protecting humanity from demons.
[3] The story unfolds in Downworld, a mystical version of New York City populated by various supernatural entities including vampires, werewolves, and warlocks, who often find themselves in opposition to the Nephilim.
It revolves around the Shadowhunter Emma Carstairs, first introduced in City of Heavenly Fire, as she seeks the answer for her parents' mysterious deaths.
[citation needed] The Wicked Powers will be the sixth and final set of books to be published and serve as the conclusion of The Shadowhunter Chronicles.