Follow the purple line to the kick-off point (on the ridge, on the far side of the camp from the Chimera; about 450’ from the corner with the dragon - the green diamond)
Observe what is going on - in particular, someone with arcane sight...will be able to see magical surprises & illusions (neither of which myself or Rune is equipped to spot at long range).
Give the dragon a wake-up call with our best long-range effects...Hopefully put it down. If it survives, it either comes to us or flees.
Either press the assault or break off (Devlin can go straight into the earth, or use a Ride the Blast to jump away). Currently I’m leaning break off - Mae’s knowledge check says the dragon’s a sorcerer 13, and someone was throwing earthquakes at the village; it wasn’t the dragon - so there’s another significant caster in the camp…