SureAI

I have placed all the barrels of gunpowder in the safe area, but I can't see how to release Gabor. I see a beam and a 'loose iron rod', but I can't move or use either of them. I went on the other side of the wall and talked to Gabor, but he does not respond. What am I missing?

When Gabor is done talking and you get a quest update, take the iron rod. (Activate using Spacebar.)

The trouble was - he wasn't talking.

I found the problem. Although I moved the barrels that were in danger, there were still two of them near the fire toward Gabor, and the sequence started after I had moved those two to the 'safe' area.