Cassandra Clare took to her Tumblr on Thursday to answer some questions, and one of them was about what her plans are regarding future series.

She let slip an interesting tidbit: she has plans for a fifth Shadowhunter series, which she referred to only as TWP. She listed all her series in what seems to be the internally chronological order:

“The five Shadowhunter series are TiD, TLH, TMI, TDA, and very far down the road, TWP. Don’t even ask about that one! It’s too far in the future!” (Original post)

For fans who may not be familiar, the series referred to are The Infernal Devices (a recently completed prequel trilogy), TLH (we only know that it follows the next generation after The Infernal Devices), The Mortal Instruments (the six books that started it all, with the final book “City of Heavenly Fire” coming out next March), The Dark Artifices (trilogy set 5 years after TMI, with Book 1 – “Lady Midnight” – due in 2015), and now TWP.

Keeping in mind how many of these books Clare has yet to write, we won’t see nor hear of TWP for at least another six years; if Clare takes a year per book as usual, then not until 2021. But knowing how passionate Clare’s fans are, the speculation doubtlessly begins now!

Once this fifth trilogy is complete, that will put the total number of Shadowhunter books at eighteen, not even counting the Magnus Bane Chronicles, nor the Codex. Do you look forward to reading all of them? Or do you feel that this may be too much of a good thing, and would rather Clare write entirely new novels?