This guide helps players with a specific quest of chapter 2 for Roche’s side in The Witcher 2. It has a map, legend, and walkthrough to show you exactly how to complete the quest.
Background
With her dying breath, Sabrina Glevissig, King Henselt’s previous royal advisor, cursed the king with a terrible curse because he sentenced her to death. It’s up to you to lift the curse with the help of Dethmold.
Walkthrough
King Henselt himself and Dethmold will tell you a lot about the curse which befell the king. You’ll learn how Sabrina died, what kind of curse she cast, under what circumstances she really died and a lot of history on the blood curses. After extensive dialogs with both the king and Dethmold (#1) you’ll be given a task to investigate the pyre where Sabrina was torched.
Near Sabrina’s torching site (#2), you’ll also stumble across a pair of soldiers for the side quest Lost Lambs. You can agree to help them, after investigating the area. Examine the pedestal, the soil, the wheel and the various items around the site.
Examining the items around the circle will reveal a square coin for the Conspiracy Theory quest and a letter. You can also take a nail from the wheel itself, as someone was pulling them recently and maybe one of them can shine some more light on the subject. Examining the soil reveals that only one person walked closer to the pedestal, and that’s the one who thrust Sabrina with a spear to let her cast the blood curse. Also there are cat tracks. Triss told Geralt once that cats and dragons are the only animals that can draw the Power, so it’s clear that Sabrina’s pyre still holds a great deal of magical energy.
After fully examining the place, you’ll conclude that there are two leads at the moment, the nail thief and Sabrina’s cultists. The only way to lift the curse is the recreate the whole event again and cut it off on spot. You’ll need to do a magical ritual involving King Henselt himself. Even though the curse will be lifted from him, the mist area will still persist.
Next step would be to talk to the relic peddler at the cantina (#3). Doing this is optional but adds a bit to the depth of the quest. The peddler will reveal some details about Yahon, the soldier who stabbed Sabrina upon her request. He’d also like to get his hands on Yahon’s spear and he won’t give any details on its whereabouts. After the discussion, he’ll send you over to the Visionary in the ravines (#5).
On your way to the Visionary, you’ll meet a group of soldiers (#4) who’ll be fighting a pack of rotfiends. Help them out and even if they all die, you’ll get a quest called The Path to Visionary, which continues the story about the Visionary and is necessary in order to progress with this quest.
Having completed that quest, you’ll be heading back to relic peddler (#3), who lied to you about Yahon’s spear as it is, in fact, in his possession. Unfortunately for you, he sold the spear a while back, so he wasn’t really lying, except for the part that he knew where it is. To find additional details on the location of the spear, you can either pay him, or use Axii, intimidiate him, persuade him… anything works in here. You’ll learn that the spear is in Iorveth’s hands, who is on the other side of the mist, in Vergen.
Since there’s no way to cross the mist all alone, you can ask Dethmold (#1) to provide you with some sort of magic protection. You’ll receive two quest items: an Emissary’s flag, De Tansarville’s protective amulet and a particularly useful chest piece 
Zireael’s Armor. You’ll also gain 2050 experience points. Dethmold will give you the quests Death Symbolized and Hatred Symbolized. Also, make sure to get his grimoire and magic dust while you’re at it. He’ll hand them over at king’s expense. You might have also got these quests earlier if you talked to Zyvik, who wanders around the camp.
Once ready, head over to the mist entrance. There are several of them, but the closest one is at #7. On your way there, Zoltan (#6) will stop you and tell you that his stay in this camp is far from friendly, as everyone makes fun of him because he’s a dwarf. You can offer to help him cross the mist, to which he’ll happily agree.
Inside the mist, make sure you’re following a purple sphere. That’s De Tansarville’s amulet at work. If you ever lose track of it, use your own witcher’s medallion to reveal it again. Anyway, you’ll be crossing the mist at #8. That’s the exit to the Vergen’s side of the valley.
Over on the other side, you’ll meet the elves in the burned-down village (#9). They, of course, play hostile at first, but Zoltan will interfere and with a bit of diplomatic persuasion, they’ll let you pass to the gates of Vergen.
Right at the gates of Vergen (#10) you’ll be greeted by one of your old friends Yarpen Zigrin. There will be another dwarf next to him, called Skalen Burdon. They’ll be glad to chat with you and you can also find out a bit more about where the Dun Banner standard is for the quest Death Symbolized and that Saskia’s sword is actually Vandergrift’s sword, the symbol of hatred.
At this point, you can go to the dwarven catacombs (#12) to recover the standard. To enter the valley that leads to the catacombs, pass through the small tunnel at #11. The quest Death Symbolized is further discussed on its page. After you find the Standard, you can head to the tunnels (#13) to meet with Zoltan.
Navigating the tunnels can be pretty confusing, but there’s really only one way you can go, with a few short side ways. The most interesting thing beside meeting with Zoltan is the Blood Sword found at #14, guarded by a bullvore. It is the best silver sword in Act II. Zoltan’s located at #15, behind a bullvore.
Zoltan has failed at lying and getting the sword, but he brought Saskia. As she has a very noble personality, she’ll give you the sword to light the curse from the king and free the ghosts of their restless battle. This completes the quest Hatred Symbolized. You’ll also learn that Iorveth lost his spear in a dice poker match with Skalen. This starts a new quest called The Spear of Destiny. Once you win the spearhead, you can return to the other side of the mist (#8).
As you come out of #7, you’ll meet Roche. He’ll tell you that Nilfgaardians suddenly attacked. They were waiting at the entrance to the fog for a shipment of figurine. You’ll learn that the figurine is, in fact, Triss under a spell called Artifact compression. Some girl brought it from the other side. This triggers the quest Where is Triss Merigold?.
Once you’ve regulated that one, head over to Henselt and tell him about your findings on the other side of the mist. He’ll be very pleased and will move out at once with you to the site where you’ll lift the curse (#2 – Sabrina’s pyre).
Over at the pyre, the king will guide you to the spot where he stayed at during the torching (#16). Once on the hill, you’ll explain to the King what he has to do in order to start lifting the curse. Remember the grimoire and the magic dust that you had taken from Dethmold? They’ll come handy now.
Performing the ritual isn’t difficult, just follow the provided picture. If you’re starting from Pixie ring, move the king to petrified bread, then black candles, goat’s skull, scorched tree, raven’s corpse, sour milk and finally pixie ring. The ritual will start (#2) once you enflame the powder with Igni sign and you’ll be fighting wraiths, a lot of them.
After killing around 20 wraiths, the ritual will be ended once Henselt thrusts the spearhead into Sabrina’s ghost. Curse will be cut off from Henselt, but it still isn’t completely lifted (the mist). You’ll gain 2250 experience points, and Henselt will call you to his tent where you’ll receive the medallion for the quest Faith Symbolized. The quest The Blood Curse is completed and further details of the story are explained during the Faith Symbolized.
