When I tried to enter swamps for the first time, I could not speak to Lector at all. Tried reloading saves, reentering area, running around, all to no avail. When Lector was 'mysteriously' killed and resurrected, I could speak to him, but on beginning the quest to rescue the stalker, it would instantly self-cancel. What work-around might there be? Is this quest required for the area?