In Lak'Ech

Where do I find the 4th part? I've got the blade, hilt and the red gem. Answer as a hidden spoiler pls.

Hi guys! I've been looking for a place for a while and I still didn't find. It's no big deal. The place is named "Elmshore". It's a bounty quest we get at Caed Nua. You get four of them at the first time you go there, I did 3 of them and this one I can't find where to go. Can anyone help me out? PS. I'm new here, I don't know if this would be considered a spoiler... seemed the best forum to create this post.