To be merged with existing walkthrough if necessary:
Just outside the herbalist's house in the village, a group of guards have surrounded Malena, accusing her of luring two guards away into a Scoia'tael ambush.
Geralt intervenes and agrees to check out the cave to which the guards were presumably lured.
Meet the Guards and Malena at the cave, which is on the path that Geralt, Roche, and Triss took from the boat to Flotsam.
There is a "Place of Power" just outside the cave. Hit Z for a boost, examine the blood slick on the way in, then enter the cave.
Once in the cave, climb down a few ledges, and load up with potions. You will see a body and a chest ahead. When you enter the area, Nekkers attack in a swarm. After the Nekkers are dead, proceed through the cave. There will be one or two more along the way.
Climb up the next ledge, and the bodies of the two dead guards, riddled with Scoia'tael arrow, will be up ahead.
Continuing on to the end of the cave, leads to a ladder to a locked trap door.
Return to the guards and tell them about Malena:
- Tell them the Scoia'tael killed the guards. They will be ready to string Malena up. But you can allow her to "show you something." When you and the guards follow her, she leads you all into an ambush.
- Tell them Monsters killed the men. Malena will be grateful and tell you to meet her at the waterfall -- which will be an ambush you get to solo (with the help of a few drowners). Malena runs away leaving you to face a fight. After the ambush, Malena can be found in the ruins southwest of the lake.
- Just edit the walkthrough as you see fit - No one "own" the page, so add to, or clarify it. I believe a walkthrough should be as precise and factual as possible, without any flourishes, (which many on this wiki aren't).