The many fans of Cassandra Clare’s The Mortal Instruments series are counting down the days until the March 8 release of Lady Midnight, the first book in a new series, The Dark Artifices (S&S/McElderry). Bookshelf caught up with Clare in a rare moment when she was not writing….

The new series is related to The Mortal Instruments books – is it a prequel? Sequel? Companion?

It’s set in the same world as Mortal Instruments and it’s sort of a continuation of the story but with different main characters, so I guess you could call it both a companion and a sequel. It’s complicated because by the time I finish, I will have five separate series set in the same world. This is the third series, and there will be three books in this one – Lady Midnight, Lord of Shadows, and The Queen of Air and Darkness. I’m working on Lord of Shadows now. After I finish this series, I’ll start The Last Hours, which will also be a Shadowhunters series, but set in 1903 in Edwardian London. The last series will be called The Wicked Powers but I can’t say a word about that yet. I actually had to hire an assistant to help me keep track of the all the plotlines and the family tree, write a dossier on each character, make timelines of events, and take notes on the mythology. We published some of this as The Shadowhunters Codex, which included the history of the Shadowhunters and a lot of stuff about the different kinds of weapons they use.

Wow, that’s a lot of writing, especially since Lady Midnight clocks in at 720 pages. Do you think you’ll ever write a series that isn’t about the Shadowhunters?

With what time? Although, I do collaborate with Holly Black on the Magisterium series. Our third book, The Bronze Key, is coming out in September. David Levithan is our editor and he thinks the way we work is just ridiculous. Since the stories are told from the point of view of one person, Callum Hunt, we wanted the voice to be totally consistent so I write 500 words and then give the computer to Holly. [Clare and Black live about a mile apart in western Massachusetts.] Then she writes over my 500 words and adds another 500 words. Then she gives it back to me and I do the same. Our acid test for whether this was working was that we gave the first manuscript to our mothers to read and they couldn’t tell who had written what. It drives David crazy but it works for us.

You always have some cool contest or giveaway for your readers when you release a new book. What are you planning for Lady Midnight?

Well, I really wanted to be able to sign the entire first run of Lady Midnight but then they told me how many books that would be (at least 600,000) and I realized no human being could do that. I’m aware of what signing 150,000 copies [of The Fault in Our Stars] did to John Green. So I remembered that when Suzanne Collins hurt her wrist and couldn’t autograph any copies of Mockingjay, she had a special stamp made that she used during her tour but then retired, never to be used again. So I asked if we could create some kind of unique stamp and I would stamp as many books as I could, which still turned out to be less than they were going to actually print. So we drafted a bunch of people with connections to the book – the designer, the editor, the president of Simon and Schuster – and we had stamping parties to get it done. So if you get a stamped book, it was done by me or by somebody very close to the production of the book.

All this and a TV show, too! Freeform [formerly ABC Family] just launched Shadowhunters, its own series based on the books. Did you get to have any input?

I’m actually not involved at all. I mean, I did visit the set but I am as clueless as the next person as to what will happen next. Well, I do know a little, but I wasn’t involved in writing it and I didn’t have right of approval or get a consultant fee or anything like that. But, of course, all my readers always come to me with questions about it. That’s the thing about having a close relationship with your fans: they think to ask me first even though the TV series is really a completely separate thing that doesn’t have anything to do with me or the books. I think that will change. I think fans of Pretty Little Liars have finally separated the books from the show. [The show] is a riff on my work, not my work. A lot of people want to know, ‘Why aren’t you involved?’ and the real answer is, if I insisted on being involved, nobody would have bought the rights to make it. That’s just not the way these things work except in very special circumstances. And I’m okay with that.

Lady Midnight (Dark Artifices #1) by Cassandra Clare. S&S/McElderry, $24.99 Mar. ISBN 978-1-4814-7857-1