You help the brothers salt the entrances to the room, and you patiently listen to their explanation of why the demons can't cross salt lines. Once that's done they tell you that they are going to summon the demon using a special magical ritual and then they will kill it with a special knife of theirs. They say they'll be back in a few hours and that you aren't for any reason, supposed to leave the room.
Once they leave you find yourself wondering. Did they say a MAGICAL ritual? That's sweet! You smile as you picture yourself casting spells and such. Before you know it, you've spent the entire few hours daydreaming about such things.
When the brothers come back and tell you that the demon is dead you hug them both and tell them teary-eyed that you are ever so grateful. They look mildly pleased that they actually got a thank-you for once.
When you leave you know that you'll never see them again. No, you will go back to college and they will continue hunting, so you wave good-bye to them and smile, knowing that the world is better off with them around. And perhaps, if you ever get tired of school, you might try and become a hunter yourself. But then again, maybe a quiet life is the one for you. Choices, choices, choices...
THE END! Congrats! You survived your Supernatural experience!