Jesenda (kneeling next to Queen Amree)( 983, -26, -894 ) Copy/waypoint 983, -26, -894 suggests setting up a false grove in order to lure the assassin out into the open.
Click the boat to travel to Elddar Grove. Meet Queen Amree's guards there. ( 709, -17, -279 ) Copy/waypoint 709, -17, -279
Place the 5 false flower buds and sapling in the grove encircled by Faydark vines.
Hide in a nearby fern and wait for the assassin. ( 672, -17, -242 ) Copy/waypoint 672, -17, -242
When you surprise the assassin, he casts an illusion that spawns around six additional assassins. Slay them!
The true assassin is knocked to the ground at the end of the fight. Question him to discover what traitor employed him.
Talk to the assassin immediately. If you wait too long he will port himself away, and you will have to repeat the fern-hiding and assassin-slaying again.