He Saved Her Life
Once the contractor came, he started looking in the wall. There was nothing obvious here. So, he started drilling the wall and looking inside. He soon saw the main cause of the strange behavior and why Thor was barking there all day long. It was bad.
The supporting bean was completely rotten. The dog somehow was able to smell that and tried to warn Nancy about the risk. Yes, the risk was massive. The contractor was unable to believe in all of this and the previous story. This had to be solved immediately.