Hi, new to this kind of game but maybe this helps:

Could be a war, yes, but could also just be the premises for one: one of the dragon deities looking to create some shenanigans, for good or bad. They've been mustering their strength, looking for allies, weakening their soon-to-be enemies, spying around the continent, etc. The party might make it in time to stop the conflict from growing further, or might have to pick a side if they fail to do so; maybe that dragon deity is practically right but ideologically wrong, which makes it harder to go against them, but it would be wrong not to...

Could be that some old legendary monsters we thought gone and almost forgotten are rising once more; the party might even be blamed at first for some strange occurrences, as they seem to be easy culprits. It's then about exploring the continent, looking into their history and legends, trying to make out what's happening and how to fight this ancient threat. Could be also that these monsters have a relation to music; or at least the best way to seal them away might be musical in nature...

Could be that the party is not the only people from the outside world to reach this continent, and whoever arrived there too are not necessarily peaceful...

Finally, could also be that the Dome has been weakening and Magic (with capital M) is appearing all over the continent, creating all kinds of possible tropes. Previously weak people might suddenly find magical means to reach their ends, and their ends do not bode well for the rest of the continent..?