The Ballista

Quest is given to you by Roche upon entering the frontyard of Loredo's residence, during the main quest line of Chapter I. Your objective is to disable to the ballista.

Talk to the prostitute nearby, you can ask her to "surprise your friend". In order for her to accept your request, you can either pay her for the job or defeat two men nearby in arm wrestling. While she is giving oral sex to the guard of the ballista, you can go to the ballista and remove a piece of it, thus completing the quest.