Cassandra Clare, the YA phenom best known for her Shadowhunters series, is being sued by author Sherrilyn Kenyon for “for trademark infringement, copyright infringement, unfair competition, false advertising, and trade dress infringement,” according to a lawsuit filed in Kenyon’s home state of Tennessee on Feb. 5. The author seeks compensatory damages for lost profits based on similarities between Clare’s Shadowhunters series and Kenyon’s own Dark Hunter series.

Kenyon alleges that Clare copied parts of her Dark Hunter series (first published in 1998), resulting in Clare’s Shadowhunters series becoming too similar to Kenyon’s own. The lawsuit outlines these similartities here: “Both the Dark Hunter series and the Shadowhunter series are about an elite band of warriors that must protect the human world from the unseen paranormal threat that seeks to destroy humans as they go about their daily lives. These hunters, whether ‘dark’ or ‘shadow,’ preserve the balance between good and evil, protecting humans from being consumed or enslaved.”

Kenyon also takes particular issue with Clare’s use of the term “shadowhunter”, as Kenyon owns trademark rights to the terms “Dark-Hunter”, “Dream-Hunter,” and “Were-Hunter.” The lawsuit alleges that in 2006, Kenyon’s fans alerted her to Clare’s use of the term “darkhunter” in her work, which Clare subsequently removed in favor of “shadowhunters.” Clare also removed “any reference to “hunter” (whether “shadow” or “dark”) from the title,” publishing the book in question as The Mortal Instruments: City of Bones.

Despite “continuous assurances from Clare and Clare’s publisher that she/they would not expand the use of the ‘shadowhunters’ term or adopt it as a trademark,” the lawsuit states, “Clare has persisted over time in expanding her use of the term ‘shadowhunters’ from a mere description of her protagonists, first to a tag line on the cover of her works and eventually to a complete rebranding of her works so as to be confusingly similar to the Dark Hunter series.”

As further evidence, Kenyon’s suit cites both the books and the various television and film versions of Clare’s Shadowhunters — like the new Freeform series, which also airs on Netflix — as well as the similarities between Clare’s Shadowhunter logo and Kenyon’s Dark Hunter symbol, which even caused confusion at the publishing level:

The Dark-Hunter Series and the Shadowhunter Series are so similar that Clare’s own publisher mistakenly printed 100,000 copies of a Shadowhunter Book referencing the Dark-Hunter Mark on the cover. Upon written demand by [Kenyon], Clare’s publisher destroyed tens of thousands of the Shadowhunter Book that contained [Kenyon]’s Dark-Hunter Mark on its cover. Despite the destruction of tens of thousands of copies of this Shadowhunter Book, thousands of Shadowhunter Books including the Dark Hunter Marks on the cover have now been sold and substantial commercial confusion has resulted.

UPDATE (2/11/16): EW has received a statement from Clare’s attorney, John Cahill, which says that Kenyon’s “lawsuit failed to identify a single instance of actual copying or plagiarism by Cassie,” and notes that some ideas Kenyon claims Clare stole, like having “normal objects…. imbued with magical properties such as a cup, a sword, and a mirror,” have long been part of the human storytelling process.

The statement continues below:

“Cassie was both surprised and disappointed that Ms. Kenyon would file this baseless lawsuit, a decade after the debut of Cassie’s books. Kenyon is wrong when she claims that Cassandra Clare or her publisher made any agreements about using ‘shadowhunters.’ Cassie never gave Kenyon any assurances regarding this and, although she would have preferred to resolve any concerns that Ms. Kenyon has or may have had, Ms. Kenyon never contacted or spoke with her.”