Where is Triss Merigold? | Paths and consequences - act 2 The Witcher 2 Choices Guide

Although an important part of this mission is the choice of either to kill the she-troll or to help her, but is not too much to reflect on the future gameplay (only a little help). You should consider help the she-troll to obtain the troll's horn. During visit in the Kaedwen's camp definitely the better choice is tearing through the camp (much cheaper option).