This quest will involve you hunting down the second assassin who tried to kill Henselt. You will have to travel around the camp and try to find evidence and intelligence before setting out to kill the second assassin, thus persuading Henselt to give you his medallion. If you completed the Lost Lambs side quest, head to the northwestern side of the camp, by the point of the valley ahead. You will find an elven prisoner here. You can glean a little more information on the assassins and your enemies from him.
Afterwards, you will learn that you will have to drink a potion. Meet up with Dethmold and he will fill you in on the details. Speak with Myron on the bench outside of Dethmold’s tent to obtain a formula for the potion that you are supposed to drink, and then talk with Gadwell to get the ingredients. When you have the ingredients and the formula, head into the meditation menu and craft the potion. Drink it from this menu as well. Now return to Dethmold and speak with him. The sorcerer will link your mind with the dead assassin’s, meaning that you can see into his past. Using this information, you will be able to hunt down the second assassin.
You will now be in the body of one of the assassins. Follow the other assassin, Serrit, towards your secret hideout. When you reach there, a brief mention of the attempt on Henselt’s life will be made, and Letho will appear. He will have been waiting for you. Once you get to walking again, be sure to follow Serrit very closely. Letho will have rigged up the entire place with tons of booby traps, and one wrong step means death, or worse. This will lead you back to the beginning of the flashback, meaning that you will have to play through the entire thing again. Not fun. Stick close to Serrit to pass safely by the traps. As you speak with Letho, (Spoiler) he will mention Sile. It appears as if the sorceress has been in league with the assassins the whole time. (End Spoiler.)
This will segue in to another vision. You will be walking around the camp, waiting for the right moment to infiltrate it. If you are caught by the guards, the vision will end and throw you back to the beginning, just like with the traps. Wait until the guards move apart from each other and walk away. Move in stealthily, crouching so as not to make any noise. Proceed to the guard with his back turned to you and sink your knife into his back. This will trigger another vision.
You will now find yourself talking about Loc Muinne, where you will spend the final Act of the game. Letho has apparently gone there already, or at least that’s what the assassins will say. This will lead into a section in which you must battle a large group of guards. Try hard not to die in this section, as again, it will boot you back to the beginning of the vision, or your last save. Block the guard’s attacks just to be safe, and focus more on parrying than on lashing out yourself. If you need room to breathe, cast Aard. It shouldn’t be too hard to kill all of the guards at this point. Now you will move up to the point where Geralt fought the assassins. This means that you will be fighting yourself in a surreal turn of events. Try as you might, you won’t be able to kill Geralt, as these events have already happened. Just let him hit you twice, and you will die. Again.
Exit the vision as the assassin dies and return to Dethmold with your findings. (Spoiler) Tell him that Sile is a traitor and that Letho went to Loc Muinne. (End Spoiler.) You will have to re-equip your Steel Sword after this. Head into the area ahead, and get ready for a Gargoyle battle. Watch out, because when it dies, it may explode. Dodge around behind it and hit it with heavy blows. When the enemy falls, roll away to avoid the explosion. Follow the same path that the assassins did earlier. This will lead you into another battle against a Gargoyle, along with a Golem this time. Kill the golem and you will acquire the David ability, which will increase the damage that you deal against large enemies by 10%. This is incredibly handy to have during boss battles later on in the game.
Up ahead, (Spoiler) you will find Serrit lying in a puddle of blood. He will be dying. As he passes away, he will tell you that it was Sile who did this. He will also trigger a flashback of Geralt’s past, focusing on Yennefer and her location. (End Spoiler.) This will mark the beginning of the quest Returning Memories. Loot Serrit’s corpse to find Serrit’s Notes, Negotiator, a pair of Boots, and Diagram: Conflagration. Leave the area and head back to Dethmold’s tent yet again. Speak with him and he will hand over the medallion necessary to complete Faith Symbolized. This will mark the end of the quest, for now.