The event starts after receiving the mail Additional Karka Attacks.
1. Go to Caledon Forest and find Warden Lochlain
There is also event to kill young karka (help him with this event), which starts next to Warden Lochlain, so he can be dead when you find him!
2. Finish the event: Drive the invading karka out of Morgan’s Spiral.
I finished this event but it seams to be bugged as well. The NPC will tell you that this was the first time that he saw karkas and that he believes that he know his names from his dream.
i am there and nothing hapends