It wasn't peaceful in the Calder's family home, Lucas was truly gone, the same was true for his wife and to think that he had imprisoned her for over two years, he was just too beastly.
Jonas was someone who was a perfectionist but the news of Lucas and all his dirty laundry that had been aired out for everyone to see, tarnished everything. He couldn't punish Lucas as the person was dead in the fire.
From what he had heard from the investigators, Lucas and the rest of the people were killed in the fire alive. It was arson and whoever did that, probably died in that fire too.
Ruby was the one who was more pitiful as she died in that fire tied to the bed, looking at the dead bodies who were near the bed where Ruby died, Jonas didn't need anyone to tell him what had been happening there.
For a child who had done so many bad deeds in his life, to think that he will die under the hands of others, made Jonas so mad he wanted to kill Lucas for the second time.