Received from: Automatically after completing A Rough Landing.
Step 1: Search for traces of the kingslayer in Flotsam
After running from Iorweth's men, you will see him accompanied by the kingslayer. You have to take a look around the city in search for more hints on the assassin.
In order to continue, you have to complete the following missions: Indecent Proposal, The Kayran and The Kayran: A Matter of Price (The Ballista and The Kayran: Ostmurk are optional)
Step 2: Head to the prison ship. Follow Triss
After finishing the above missions, right beside the gate to Loredo's residence you will meet Triss. You will tell her that there is a Scioa'tael on the ship - Triss will add that it's Iorweth's right hand - Ciaran. Follow your companion to the ship (M7, 28). Right before the entrance you will come across two guards.
Notice! If during Indecent Proposal you accepted Loredo's offer, the guards will let you through without making any problems.
In the other case, you will have to use intimidation. Go below deck and head to the very end. You will find a dying Ciaran there.
Step 3: Calm the wounded with Axii
In order to calm down the elf, you will have to use Aard together with Triss - in fact the only thing you have to do is keep quickly pressing the left mouse button. You will have to try again in case you fail. You will learn that the kingslayer - Letho - has been using the Scoia'tael from the beginning and is planning to kill Iorweth. In order to find more details, you will have to use one of the options: intimidation, Axii hex or persuasion. After talking with Ciaran, your memory will return. Triss will tell you that a certain flower - The Rose of Remembrance - can aid the recovery. You also have to choose if you want to take Triss with you or not (a detailed description in the proper mission).
You will unlock: Returning Memories.
In order to continue, you have to complete The Rose of Remembrance.
Step 4: Talk with Zoltan about the Scoia'tael
Zoltan can be found at the tavern (M7, 3), sitting by the table with his friends. Tell him you have to meet with Iorweth - from your conversation with Loredo you can remember that the dwarf has certain contacts within the Squirrels. Your friend will agree to take you to the meeting place.
Step 5: Go meet with Iorweth. Follow Zoltan
Leave the tavern and follow Zoltan to the woods. Eventually you will reach the Squirrels meeting point (M8, 19). Geralt will sense their presence and tell Zoltan to tell the password - Iorweth's men will appear. You will be granted a permission to meet with him, but in a different spot - once again follow Zoltan to Iorweth meeting place (M8, 20).
Step 6: Kill the Aracha
After getting there, you will fall into a trap - you have to kill the Aracha. The fight shouldn't be too hard for you, considering there's Zoltan beside you. Your companion will effectively draw the monster's attention. Don't however forget about Yrden, which will make the task easier. Also look out for the poison which the monster spits.
Notice! The Crab spider, to be precise his eyes, is connected with Melitele's Heart.
After getting rid of the monster, Iorweth will arrive accompanied by archers, who will start aiming at you. Try not to irritate the elf, as it will end tragically for you. Tell him what you learned from Ciaran - that Letho is planning to kill him. The elf won't want to believe you, but in the end he will agree to look into the matter.
Notice! If you try to be too harsh, you will get shot.