It all starts with a half formed thought.

I was getting a bit bored with the Bloodrose campaign, so I started thinking of revisiting old ideas. One such idea involved Tiamat imprisoning Iuz in order to take over his earthly realm...
That was it, that was as far as thought had taken me.
Slightly irritating that.
Leavin' me hanging like it did. I do what I usually do in these circumstances. I start searching for premade adventures to string together into a general campaign arc. I don't really like using the premade stuff, but sometimes they come in handy for stirring up ideas and directions you've never thought of going. Keep in mind I still had no answers to some mildly important questions. Why did Tiamat need Iuz out of the way?  What was her ultimate goal? How did she imprison him? Where?
I wasn't getting anywhere when I finished stringing together the premades, so I tucked it in an  envelope and told myself I'd come back to it later. Recently, I revisited everything I had written down for what I was calling "Tiamat's War".
So, now I'm sitting here with some half formed thoughts, this is when I let the brain of the chain and write down whatever makes the grey matter tingle. What follows is the thought process. At least most of it, I'm leaving out the brief research forays onto Wikipedia.

We start with a powerful entity imprisoned by a different powerful entity. (The original concept)

Demon Queen imprisoned by Great Old One. (yes those Great Old ones...)

Great old one using the resources of her realm to search for the Kingdom Stones, in  order to restore the sorcerer kinds to their rightful lands.

Scylandra (Demon Queen) is daughter of the Sisters of Madness (Baba Yaga and her 2 sisters)

Oooo, I get to use Baba Yaga's hut!

Who knows about the Kingdom Stones?

Hidden Prison (privately funded by a cabal of evil dukes) is a prison for political dissidents.

PCs must get to the prison before the cultists, so they can question a specific prisoner.

Among the prisoners is a God/Demi-God that has forgotten who he is. (I know I've heard of this story somewhere else, but I'll be damned if I can remember where)

Maybe he's just crazy? Maybe he knows where something g is hidden. (the Kingdom Stones)

There you have it, this is all scribbled on a legal pad that I carry around with me. These ideas will continue to percolate for a while, and I'll add to them as inspiration strikes. Eventually, it might work itself into a full fledged campaign.