At many occasions in the game you will have to make a choice - such as this when you were to decide whether to go to the laboratory or fight the frightener. Every choice has consequences, some of which appear much later in the game. Most of the time they're not essential to the game - it's just a matter of slight differences in certain quests.
There are choices, however, that alter the whole story of Chapter V, as well as the game's ending. Generally it's about whether you join the Scoia'tael, the Order of the Flaming Rose, or you decide to remain neutral:
- in chapter II: Q2.59. Force Recon;
- in chapter III: Q3.88. Gold Rush;
- in chapter IV: Q4.107. Free Elves.
Remember that certain decisions can cut you off from some options in the future - you can't just swerve between sides every time you are to make a choice. For example: choosing side in Q3.88. Gold Rush leaves you with a choice of supporting the same side in Q4.107 Free Elves or remaining neutral (you can't change sides).