The climax is the most intense moment of the story that occurs just before we learn the outcome of the main conflict. In this story, the climax occurs when Boaz kills the intruder and then shaves his face. It is then that we know that Boaz has been right about his son all along. Boaz has also known that Campbell was the killer, but he was afraid to tell anyone because he knew they wouldn't believe him. People had already judged his son and Campbell, and they would have never accepted Boaz's version of the events.
I believe that the climax, or turning point of the story, is when Wood kills Boaz's son and the house burns down. It is at this point that Boaz loses his exuberance or lust for life. Like the house, he becomes a shell or skeleton of his former self. The resolution occurs when he kills Wood and we are told it's Wood that was the culprit all along.