Disclaimer: Everything from HP books belongs to JK Rowling
You know life will never be the same after tomorrow, that your nightly raids on the kitchen and running through the forbidden forest, it all ends here. You're sitting with them now, planning a big prank for tomorrow, trying not to get emotional about leaving, trying hard not to say goodbye. This isn't goodbye, you think over and over again. Please don't let this be goodbye.
You look around the table at each and every one of them. You've noticed things about them over these past few weeks, noticed about how they walk, specific ways they talk, and when you sit there thinking about it right now you wonder why you thought about it at all. Why did you memorize James gracefully running his hands through his hair or that gleam Sirius gets in his eyes right before a prank? Why remember the exact way Peter uses his quill, the frown he wears as he takes notes? You look down from James's face as he explains tomorrow's prank, you'll still see them so why, why are you prepping yourself to let go?
Because it is goodbye. You know that it will never be like this again, that none of you will ever be as in synch with each other again. After tomorrow, after you hug goodbye in your robes of gold, the Marauders will be a memory of the past, a story to tell the grandkids, something to laugh about on reunions or rare gatherings at a bar. You hear whispering all around you, whispers of your friends, of conversations of the past and you feel tears coming to your eyes. Don't let it show, you think. We aren't supposed to know that this is the end.
It will only make it harder when you leave here. Your inability to let go, to start new, will tear at your insides and rip your heart apart. You'll never be able to let go of them. Being a Marauder is all you know how to be, all you can be. If you aren't Moony, who are you? If you aren't their friend, who else do you have? You look up again as Sirius looks at you and winks. You see in his eyes, in all their eyes, the apprehension about tomorrow, the fear. You breathe in deeply and wink back at him smiling your wide, toothy grin. It's not over, it's too soon.
And James stops talking and his over enthusiastic face darkens and the four of you sit there in complete darkness, in silence. And the despair, the fear you're all feeling comes out until James gets up and walks away, not wanting to show his pain and the rest follow. You're left there, left sitting at the coffee table with your mind wondering in every direction. You're alone, and as you think that you feel at home, at ease. You have to get used to it, to loneliness, to this never ending despair filling your heart.
You look towards the stairs. The echo's of their footsteps, the sound of their voices, fade away into nothingness. You strain to hear them, to know that they truly are there. And you look to the stairs, dark, abandoned, and you know that this is how life will be. Sure tomorrow will be all laughter and smiles. Sure you'll owl often and meet at Diagon Alley. But everything will be different, your bond, your friendship, the Maruaders, it will all disappear. Life as you know it, as you love it, is over. You turn away from the stairs and look deep into the fire. This is goodbye, you think. There's no use in pretending any longer.