So the current plan it looks like is for Aern to keep the form of the poison dusk lizardfolk, splatter his throat with some blood to make it look like he's had his voicebox cut up (thereby covering the fact he can't speak) and then begin making your way up the trail to the north.
If this is indeed the plan, here are a few questions we'll need answered:
1) You have a poison dusk and a blackscale tied up and gagged. What will you do with them? Leave them here? Let them go? Kill them?
2) If Aern is walking up the trail out in the open, where will the other six be walking? A couple "tied up" as prisoners and being lead along? Others further down the trail? Sneaking along the sides in the bushes?
3) Presumably if any more guards meet you on the trail you will attack. But if no guards appear, how far north do you want to go? And if you reach the huts and temple, where/how do you want to assault it?