As the two of you exit the tower to the north, you find yourself at the ruined gatehouse that makes up the entrance of the fort at ground level.
Built into the gatehouse beneath you is a large, wooden double-door about two body-lengths tall, closed shut. While much of the tower's construction so far appears to be in disrepair, the door, you notice, must be newly built.
Further along the battlement after a turn westward is a rounded tower, similar in construction to the one you could see on the northeastern corner. It is slightly raised up from the battlements you walk along, but you don't see any movement from that direction.
You do, however, spot movement to your east. The man you saw previously leave the main hall is now climbing the ladder up to the southeastern tower. Hadrurus holds a hand out to the man to help him with the final rung up.