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If he was right next to you, and the enemy didn't react at all, that's a bug. He only stands there for a long time after crossing the river. During this time, the red-haired enemy doesn't react to anything. Then he goes to capture the castle.
I teased him for a long time in version 1.5. He tried to catch up with me, and then he went back. Eventually, he went north. Now I'm going to play this mission in version 3.0.
Added after 23 hours and 21 minutes:
And in version 3.0, I had the exact opposite bug. The red-haired enemies ran around their routes, not paying any attention to Markel. They didn't even go into the dungeon. So I easily completed this mission - there were never any serious battles here.
