Some people would say no, and that’s fine. Some authors want to write about hope or hate, for instance, so they think up a plot that shows their ideas.
What did we do in Scordril? We started with a plot idea and then realised that emphasising the themes would make the plot better. So our book shows up:
distrust and the damage caused by it
courage to do what’s right
getting on with others who are different
Our lead dragon, Scordril, has to go to a cavern where the chronicles are kept and read through the relevant entries from 100 years before, in order to work out what happened at the Great Split, when some dragons from Traprain Law layr went off to start a new layr at Musselburgh. The Split involved Jarl and something he’d done, and also a threat from nightdragons and wingriders.
These bits of information help the Musselburgh dragons to decide how they should respond when Gylning from Traprain Law arrives asking for help. The plot then grows and develops from here and the themes become “illustrated”.
My favourite is, of course, dragons getting on with humans (“others who are different”) and trusting them. Without the help of Morris and Flick, Scrodril couldn’t have solved the very great problems the two dragonlayrs were facing.
Someone asked me if dragons really exist. I can’t truthfully answer for all the dragons in the world, since I’ve not met them, but the Lothian Dragons certainly do – and if you want to read what happens when Gylning arrives, you can access the first pages here.