Where Do I Go From Here

I ask dad why I even need to do this. It makes no sense. "I can't explain it to you, it's just something that needs to be done. I wish I could tell you more, but I can't tell you." I asked him "since it needs to be done, is there a certain time that it needs to be done. Could I enjoy more time with her." "You've already had too much exposure to her. Anymore and you wouldn't be the same." I figured that that's all I get to know so I stopped asking him about it. All that was left for me to do is decide where to go. But there really is no way that I can get round it. I need to kill her. She seems like what you would call "a soulmate" and I need to put her down. At least dad is giving me the job, since I'm closest with her, I have to be the one to do it. But how do I go about "doing the deed" to the only person that I have felt this way with. I might as well give her a good send off and spend an entire day with her or something. She has lost a lot, but I should at least give her a lot, before I take everything from her. I go to school and ask her if she wants to spend all day tomorrow together, since tomorrow is the weekend. She obviously replied with yes, and her little smile that she does that I will never forget. Now I just prepare.