I was thinking of blowing up the cave, actually. Not that that would actually happen; something else would probably happen for story purposes, but that seems like a sound plan for Mithias right now. It's up to you if you want Mith to find Magnus and cause some havoc or if you want to successfully remain hidden. If mithias finds the cave, he'd probably have to confirm Magnus was there and then debate on whether or not he should effectively kill everyone inside. ...could be humans in there.

Oh. Not to mention Miller or Matt could call him off... if they knew to do that.