I dunno if you figured it out (earlier post, not last one) but by disable the Vitality option I mean if you're using the trainer to have infinite health, you have to disable that option and allow the guards to hit you and take most of your health.
When your health gets low enough, a scene will take over where you'll be captured.
Thx for the reply. I don´t use the trainer. I just couldn´t find the sewers so I let me get beaten by the two temerian guys at the entrance to the main soldier´s area and they imprisoned me. Spoiler: