It took me a while to find the right story, and to be in the right headspace. But during a trip to Montana last summer, Maas said she experienced an 'energy vortex' of inspiration in Big Sky, and the next installment poured right out.
It's just the story that was finally ready to come out of me was big - really, really, really big. I like to do parts, like part one, part two, part three. By the time I got to the end of part one it was like 400 pages long... And then I realized it was gonna be four parts. A book told in four parts.