Circle of the Mere
When you first leave the Crossroad Keep for the outer courtyard, you’ll find Daeghun waiting for you. He has news for you and Elanee. The Druids of the Circle of the Mere are still alive despite being deep within the ‘Claimed Lands’, that is to say lands controlled and corrupted by the power of the King of Shadows. Bishop of course wants to be along to lend a helping hand. You can take along 4 companions. Bishop will join you at the Mere, even if you go there with a full party.
You’ll now find the Circle of the Mere on your World Map. Once there, you’ll find that the Druids, with the exception of Elder Naevan, have become corrupted due to the influence of the Shadow. Combat is inevitable. There will be an influence check with Elanee at this point, but its inconsequential because she’ll fight with you anyway. Its hard to use area effect spells effectively in this fight, because the Druids are spaced so widely apart. I found it easiest to summon as many creatures as possible (e.g. Mordenkainen’s Swords, Dire Bears, Elementals, etc.) to tie down as many of the Druids as I can. Then have your fighters go to work on the nearest ones. Your spellcasters can let loose with single target spells. When its all done, the druids will leave behind weapons of various enchantment, +1 to +3. Vashne will leave behind a Blacksoul Sickle.
Elder Naevan will want to go elsewhere on his own, and there will not be any procuring of his assistance. If your influence with Elanee isn’t good enough, she may end up leaving you for good. This leaves you with a choice of whether to let her go and kill her. Killing her will alienate your good-aligned characters.