I'm the last person to accept the supernatural. I don't believe in ghosts or the paranormal. Still, at the center of this episode are the forensics and the work of the Jeffersonian crew. Boone has been kidnapped by the Gravedigger, who reappears from previous episodes. Instead of being put underground alive, he is in an old Navy ship that is going to be blown up. I can be forgiving of the "ghost" because everything that happens can be explained by the subconscious mind inventing what is necessary for Booth to forgive himself. This is an adventure story which draws from human experience that leads to a conclusion. I only have trouble with one moment. At the end we are led to believe that Brennan says hello to the guy while Booth talks to the girlfriend. Wish they hadn't done that.