I've had to put my head to the problem, and have finally come up with the structure and titles of the fifteen books that will comprise the totality of the Chronicles of Anuru. Five trilogies, all told. Four of those books are already written (three published, and one forthcoming in a few weeks), and 12 of them are completely plotted out.
To keep my brain on the straight and narrow, I've devised an "infographic" approach to show how they all fit together. Here it is:
The order of writing should be pretty straightforward. Once I've got Book I of the Bjornssaga, The Sea Dragon, up for sale, I'll begin writing second trilogy, The Road Into Ruin. That ought to take 3-4 months per book, given that I already have the stories plotted out and a lot of the material already written. After that's done, I'll write the three books of The Filigree Throne (the title of the first book, Centang Lewat, is the term in the Feyspeech for 'The Last Warden'); and then the last two books of the Bjornssaga - although I might write The Azure Wind before I wrap up The Queen of Summer. Once those twelve have all been published, I'll move on to the final three books that together comprise Veroldbrast (the term in the tongue of the ancient Yonar-ri that means 'The Breaking of the World'). The three titles in that trilogy translate, respectively, as 'Dragonhome'; 'Ebon Night'; and 'The End in Fire'.
Ambitious, yes. But I've put so much into these stories so far that I don't think I have any choice but to continue.
Wish me luck.