"The last part of the witcher 2 royal blood quest involves asking Henselt for his royal blood. To reach Henselt, Geralt must ask Roche (again!) to distract the guards at the gates. Then sneak around the camp, and reach the largest tent in the camp. There are two guards at this tent. Go to the back, and use Aard on the barrels. Quickly run back to the original tent, and then sneak into the king's tent when they go investigate the shattered barrels. The king Henselt is then at Geralt disposal and will gladly give his royal blood. It is best to spare Henselt, so he can just let Geralt through the gates back to Philippa, and then back to Vergen. Geralt has to promise Henselt he will lift the cursed mist in return."
