It came to me out of nowhere. The answer.
Let me bring you up to speed first.
For my 'Surreal' series, I have thought from the beginning I was going to write four books. I had names, ideas, and outlines for each.
There are two major items I had to consider, two thoughts that floated about in my head for months, and it never occurred to me until today that I could connect them together.
Item one: I was really, really looking forward to the fourth book. It was going to have heart-wrenching, powerfully emotional properties, not to mention a few other things that'll make it drastically different from the other books. I wanted to skip writing the second and third book and get to the fourth book already. I am going to have a blast writing this book.
Item two: I didn't have enough material in the third book's story. There are some very important things that happen during this time to our main characters, but nothing that would suit 80,000 words, which is my usual minimum for an adult fiction book.
I didn't consciously worry about these two problems for a while, because I was confident the answer would come to me.
And it did. A couple hours ago.
I'm going to put the 2nd and 3rd book together to create a second book with two parts.
So it's going to be a trilogy.
AND I can write the last book a lot sooner and present it a lot sooner.
It makes total sense, and I am super-excited. :)