After you have received the protective items from Dethmold, head over to the entrance to the mist enshrouded area. There are several areas in the camp from which you will be able to begin the next elg of the quest, most of which are situated along the outskirts of the area. Along the way, you will encounter Zoltan. He will have been dealing with some hostility from the others in the camp, and you can agree to help him cross the mist. Make the offer and Zoltan will be onboard with you.
After you meet up with Zoltan, feel free to head into the mist. You will see a floating purple sphere in front of you. This will mark the area that is safe from the mist. It will have been created by the De Tansarville’s Amulet that Dethmold gave you earlier. Get inside of the sphere to protect yourself. If you find yourself outside of the sphere’s range of influence and lost in the mists, you can always use your Witcher’s medallion to reveal its location and seek it out. The linear path ahead will cut through the mist and take you to the other side of the Pontar Valley.
The journey will be relatively uneventful. Cross the mists and be sure to stay near the purple sphere in order to stay safe. Once you reach the other side of the valley, you will be at the gates of Vergen. You will find the elves hiding out here. As you approach them, they will begin by shouting hostilities your way. You did help Roche over Iorveth, after all, and this angers the elves because they don’t know the consequences of what would have happened otherwise (had you helped Iorveth, the town would have erupted in violence against the non-humans.) Zoltan will quickly smooth things out between the two of you, though. He will use his ties with the Scoia’tael to gain the trust of the elves. After this, they will open the gates of Vergen and let you inside.
As soon as you enter the city, you will be greeted by Yarpen Zigrin and his friend, Skalen Burdon. Speak with them to find out a little bit more about the Death Symbolized and Hatred Symbolized quests. They will tell you that Saskia’s sword is in fact the artifact that you seek, called Vandergrift’s Sword. If you were playing on Iorveth’s side, this revelation would have taken more time to come to light. This will make the Hatred Symbolized quest a bit easier. They will also tell you about the Dun Banner’s Standard, which you will need to find in a system of caves for the Death Symbolized quest.
You should take this advice to heart and set out to complete the Death Symbolized quest right now. It will be most convenient to do at this point in the story. If you need help figuring out the answers to the ghost’s questions in the Death Symbolized quest, or if you have more general questions about the quest, check out the guide for that quest in the table of contents below. It will cover the mission from Iorveth’s side, but the way that it plays out is essentially the same.