Wizard – “Haven” [Campaign 6, Mission 4]

There are only 2 objectives: 1. Capture Isabel and perform a ritual on her. 2. Have 3 heroes survive. So, after 6-7 turns from the start of the game, I see Isabel standing nearby with one hero. I think, "Great, she has a small army," so I go after her, and she starts running away. I catch up to her in 2 turns, beat her, and think, "Okay, now I'll see the final cutscene..." but the game continues. In the end, I killed everyone, but the mission doesn't end. Has anyone else experienced this? If so, how did you fix it? And please don't tell me that I just need to start over and not touch her. :)