A Beautiful Mind

"I can't help but think that I am a terrible person," Robert started.
"Why ever would you think that?" Rose replied.
"I have such terrible thoughts."
"Don't we all sometimes?"
"No, no, you don't understand. I imagine myself as a serial killer killing hundreds of people from a submarine using a sniper rifle. I imagine myself as a terrorist visiting justice on the rich countries of the world, blowing up landmarks and burning down Walmarts. I imagine myself as a rapist, kidnapping young women and raping them repeatedly over months or years, psychologically breaking them down before slowly torturing them to death, cutting off fingers and limbs for curiosity's sake, melting their bodies and burying the residue 20 feet under in some national park."
While slightly creeped out, Rose was undeterred. "Everyone gets tempted, Rob."
"No, no, that isn't the problem. It's that I... I enjoy these thoughts."
Rose pondered in silence.
"I dwell on these things by choice! I can totally see myself being so curious about death and suffering that I kill people just to study how people die. I've always said my curiosity would be the death of me. And how different would that make me from the worst Nazi war criminals like that death doctor in the concentration camp?"
"I don't believe you could be a murderer."
"And why not? Have you never seen me angry?"
"I know your heart. And I know that your heart is a heart of love. You could never do those things."
This time Robert met her with silence.
"You don't believe me, do you? ...very well, I'll prove it. Do you have any exactoknives?"
"One, yes. It's a little dirty though."
Rose took the knife to the washroom, where she thoroughly cleaned it and disinfected it. She grabbed a bottle of rubbing alcohol on the way out.
"What are you doing?"
Rose rolled up her sleeve and began cleaning her forearm with alcohol. When she was ready, she began. "Robert, I want you to cut me from here to here," Rose explained, while marking off a length about two inches long, carefully selecting a location that was unlikely to produce any serious injury. "About a quarter of an inch deep should be enough to do the job."
"You can't be serious."
"I'm totally serious."
"I'm not doing that."
"Yes you are."
"No I'm not."
"DO IT OR I'LL DO IT MYSELF!!!" Rose screamed.
Robert, fearful that a Rose that was out of control* (Rose, of course, was in complete control, but she had no intention of letting Robert know that) would hit something serious grabbed the knife, and while holding her down pressed the knife into her skin. Rose quivered in pain but held her tongue. Then Robert began methodically dragging the knife down the path Rose had marked out--or at least, methodically only in the sense that by wrapping himself in the technical details of the cut, he wouldn't have to think about what he was doing to his dear Rose. By the time he got halfway down Rose's shaking had turned violent and she could no longer supress a long, bloodcurdling scream. Robert attempted to block his senses as best as he could and completed the task. As he removed the knife dark blood was already rushing to the surface at the top of the cut.
Now it was Robert's turn to start shaking. After pausing to stare at the blood rushing out of the wound for a few seconds, he came to and immediately looked for some way to dress it. He brought wet paper towels to clean off the blood, then applied dry ones to soak up as much blood as he could. After a few minutes the blood was still flowing as much as before, so he used band-aids to stitch together the cut as best as he could to prevent scarring, then wrapped up Rose's arm tightly with bandages.
"Look at you, Robert. You could barely do this. There's no way you could ever kill a person. Don't you see? You could never be all those awful things you imagined. They're just temptations. They're no more a part of you than the neighbour's dog."
Robert's shaking started to grow more and more violent. Rose began to hear him mumble something she could barely make out not because of volume but because of clarity. It sounded like "no, no, no." Then suddenly Robert shrieked "GET OUT OF ME!!!" and after his own series of bloodcurdling screams began to attempt to pull out his own hair.
Rose was stunned. "What are you doing?!?!"
By now tears were streaming down his face. Robert attempted to headbutt the wall of his house a few times, but failed miserably in the attempt. Then he grabbed the most solid looking textbook off of his shelf and starting beating himself in the head with it.
Rose wrestled the book out of his hands and threw him to the ground. "What are you doing?!?!"
By now Robert could barely speak. "I... did... that... to you... this... is what... I deserve."
Rose sighed. "I asked you to do this."
"You only asked because I was screwed up in the head. This happened because I'm messed up in the head. And you're starting to catch it from me--GET AWAY! Get away!" Robert weakly attempted to find something to hit his head on, and found the corner of the bookshelf, and ended up knocking a one shelf full of books over, but they mostly missed him.
"Robert..." Rose heaved another sigh. "I love you, Robert. I don't hold anything against you." And as Robert was undeterred, Rose added "I forgive you," not believing for a moment that he was in need of her forgiveness.
Robert gave no indication that he heard her, as he was talking to no one in particular in a low voice, perhaps reminiscent of a Gollum from another world, but then perhaps that wouldn't be the most fair comparison. "Forgive... forgive... no, no, can't forgive... too terrible... can't think about--AAAAAAAAAHHHHH!!!" Robert screamed so suddenly Rose jumped two feet off the floor. He began clutching at his own forehead, muttering "pain, pain" and violently ripping his hands away from time to time, apparently whenever the memories coalesced. It was as if the pain of the cut had been seared into his own soul.
Rose slumped weakly to the ground. "What am I supposed to do now?"