What goes into a crossover?

​I’ve had some questions about how I decide which crossovers to do.
I think a lot of people believe I do it just to do it, but a lot more energy goes into the decision than that.
Basically, crossovers happen when I need a specific type of character. If I already have that character in my library, why create a new one?
So, for example, I knew I wanted to tackle werewolves in my Charlie Rhodes series. I already had wolf shifters thanks to Aric and Sami from the Covenant series … and there was natural crossover ability between Zoe and Charlie because they’re both magical. So, it was pretty easy.
The same for my Moonstone Bay series. I knew I had a story where I wanted to deal with a reaper situation on the island. Hadley was going to have to interact with other reapers. I just happened to have a family of them … and guess what, two were about to go on their honeymoon. It was the perfect time, which is why Freaky Deaky Tiki in January will feature Hadley’s gang interacting with Aisling and Griffin. There might even be some group phone calls home so you get to see a few more reaper characters, even if it’s only brief interaction.
The upcoming Mystic Caravan crossover with the Wicked Witches of the Midwest is slightly different. Even though I didn’t feel our circus friends necessarily needed witches, I couldn’t get the idea of Nellie and Aunt Tillie hanging out together out of my head. It haunted and haunted me until the rest of the story started taking shape.
On the flip side, I know exactly the story I want to tell when the Covenant folks visit the Mystic Caravan Circus. I’ve known the basics of that story since I launched the series. I’m simply waiting for the right time in the narrative because Zoe’s interaction with Max and Kade will be an important stepping stone. It has to be tackled at the exact right time.
As for other crossovers, I have some ideas but they’re simply notions right now. Under my pen name, I plan to cross over as many characters as possible. There really is no order. It’s simply when the crossover can fit into the narrative without causing issues and I can wedge in the writing. That’s it.
I have a basic idea for a Mystic Caravan crossover with Moonstone Bay … and a potential visit to the island for Aric and Zoe (although that’s really just a few stray thoughts at this point). I keep notebooks all over my house, and when I have an idea, I jot them down and sort through them later. That means some crossover ideas are closer than others.
When are the next two? Ironically, they’re right on top of each other. Freaky Deaky Tiki (the reaper and Moonstone Bay crossover) hits in January 2019 and Freaky Witches (the Mystic Caravan and Wicked Witches of the Midwest crossover) hits in February 2019. As for after that, I can’t say.
I do believe Charlie Rhodes will eventually cross paths with some reapers … and very probably the circus. Will she go to Moonstone Bay? I don’t know. I’m constantly thinking and jotting down notes, so anything is possible.
What do you think? What crossover do you most want to see?

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