- slide 1 of 6
Blood of His Blood
When you get the QTE, right-click to dive onto Foltest and get him away from the blast. As the cutscene ends, hold down “S" so that you immediately start running toward the camera and away from the dragon. You should just barely make to the next tower and escape from him.
Watch for the QTE again as you run, and right-click to get behind cover and avoid the fire. Start running again once it's past, and keep it up for another tower or two. The dragon gets caught on each one, so you should be able to make it if you don't get caught on anything. As you near the end, right-click to get past the gate and trigger the cutscene.
Follow Foltest up until you find his children, then just watch the scene play out.
- slide 2 of 6
The Escape - A Short Walk
You'll regain control in your cell. You can provoke the guards and challenge the one who responds to automatically take him out in the cutscene. The other is defeated with a simple WASD QTE. Just take him out. Watch for the blinks on screen. They correspond to the position of the keys, so you may be better off just watching for their spot on the screen. The key to the prison cell is on the ground, so pick it up and leave. Move forward to the rack of weapons to get a blackjack and some gauntlets. Equip both of them and walk up the steps to reach the stealth section.
Douse the first light to get a feel for the aim, since you'll need to douse a few more, then move into the next room. Quickly go into the empty cell on the left and wait for the guard to walk past. He should stop in front of your door for a moment, for an easy knock out. Move forward and turn to the left. If you douse the torch, you should be able to fall back to the stairs and wait for the guard to approach. Once he turns around to return to his patrol, you can knock him out.
Note that you have two options here. If Aryan is alive, then he's being tortured. If he's dead, then they're torturing the Baroness Louisa. If you wish, you can rescue them from the torturer and beat the ambassador to the punch, or you can just go forward and catch them as they leave.
- slide 3 of 6
A Rescue Mission
If you want to rescue them, go to the right and into the higher room in the dungeon. There are two guards here, but they're far more interested in one of the female prisoners than you. You should be able to quickly move up behind both of them and knock them out without either being the wiser. You can calm the prisoner up here with a QTE (so that they don't call for guards), and then grab a rusty key off of one of the guards. You can then use this key on the door in the center of this long hall (near the stairs you climbed to get up here). In the closet, there's a trapdoor that you can go down to reach the abandoned lower levels.
Just walk through them until you reach the back. Once you cross the planks that make up the bridge, you will be able to peek through the hole in the wall to watch the first stages. Once you've seen enough, you can climb up the wall and drop in. I suggest that you knock out the scribe in front of you, and then draw your weapon to fight the executioner. He's fairly tough, but it's easy to take him out one-on-one. Use Aard signs to stagger him and then hit him with a strong attack. If he's staggered enough that he kneels down, then try a strong attack from behind. If you're lucky, he'll fall down and you'll be able to get a bunch of free damage. Either way, just keep harassing him until you chip away enough of his health to kill him. There doesn't seem to be any penalty for killing him (I still got the "peace and quiet" comment from Vernon).
You can then free the prisoner and watch the scene play out.
Walk out the door and don't go back into the lower dungerons. Follow the ambassador out up the stairs and just wait. He'll draw the guards down the passage to let you move up to a good spot of cover on the right side. After a few moments, he'll yell that you've escaped and send them all running back to the lower dungeon. If you stay out of sight, all four will pass without any trouble. You're free to just make a run for the exit.
- slide 4 of 6
A Simple Escape
The prisoner in here will yell for the guard, so fall back and wait for him to come in, threaten the prisoner and leave again. He'll stand with his back to the door after that, so you can easily go into the next room and knock him out. Then you can loot the key to the upper dungeon off of him. If you approach the door, you will see a cutscene of the Baroness Louisa or Aryan being led away by the ambassador.
Move up the steps to follow them, and reach a room ahead with 4 guards. Wait at the base of the stairs for one guard to be facing away from you, but close to the top. Run up and stun them, then move into cover on the closest wall. Wait for the guard in between the walls to start a patrol, and knock him out while you're in cover.
You basically just have to watch the paths and use the barrels and walls for cover to take the last two out. It's tricky but far from impossible.
Then just go to find the ambassador in the meeting room.
Walk out afterwards.
- slide 5 of 6
If he didn't wear armor, then you'll find his body here.
There are two guards ahead. Newboy will lead them away just fine, so just wait and follow them. If he's not alive, then you'll have to take care of them somehow. They are facing away from you, so good lucky with two quick knockdowns. Look to the right and you should see Triss waiting with some of Vernon's men. Just run onto the boat with her to get the final cutscene and close up the prologue.
- slide 6 of 6
All screenshots from The Witcher 2
Due to the branching nature of the game, my gameplay experience may be drastically different than yours. Please feel free to post any issues or differences in the comments.