A/N: I wish this was mine, sadly (or not so sadly) it all belongs to JKR.
The first anniversary for the battle for Hogwarts was a subdued affair. Classes were cancelled and most students spent the day in natural silence. For the older students no words were needed. Some of the surviving DA members returned to the school to visit friends and relatives, they were accepted with whispered greetings, as if even noise were enough to disturb the solemnity of the occasion. All except one, a certain green eyed man was talking, yelling even, at a painting, in a room, in a tower, that might as well have been on another continent for all the differences in atmosphere.
It was here in the headmaster's office that one Harry Potter was yelling furiously at a painting.
"You mean to tell me that if I were to go back in time and prevent Merope Gaunt from feeding the love-potion to Tom Riddle Sr. none of this would have happened!"
"Yes, Harry, you have the chance to change history"
"Change history! Change History! Why did you in your obviously infinite wisdom not do this already! What were you thinking? Merlin, all this time the only thing that needed to be done was to stop one sad, lonely girl from making one mistake! What were you thinking, no really, what on earth were you thinking?"
"Harry, despite being a portrait of him I am not actually him, I don't know what I was thinking I only know that it was thought."
"Because that is so much better than actually knowing why you let all those people die when you had the solution."
"Time is a funny thing; if you were to do this none of those people would have died at all so it really doesn't matter when it gets done."
At these words the infuriating portrait of Albus Dumbledore smiled suggestively at Harry and then looked pointedly at the chart of ruins on the desk. "All you have to do is follow the spell I told you about and it will take you there". Harry let out a noise that sounded very much like an angry dragon. A painting of a lesser wizard would have fled at this stage, sadly for this painting tact was never incorporated into its creation. "How would I get back, if I hypothetically did choose to go?" Harry asked. "Well" the painting shuffled slightly in its chair,
"You won't actually come back; there is a minor side effect that means if you successfully alter time, you will become trapped in an alternate time strand. Terrible things happen to wizards that meddle with time Harry; you will be separated from everything you have come to love for the dream of a better world."
Harry's face took on a menacing expression and the painted Dumbledore began to creep towards the edge of his frame.
"So you are telling me that by choosing to go back in time, this time line will not actually change, I'll just give up any chance at enjoying the peace to make a nice new timeline, everyone here will still die"
"No, I am telling you that this timeline will become a dead end. It will just stop where it is, all the souls will return to the place souls go. Many will be born as different people in the new line"
"Why should I do this?" Harry looked at the painting with finality; his confused thoughts began to quieten, knowing that the answer of the portrait would decide the end of this conversation. It was quiet, so quiet that Harry almost didn't hear what the painting had to say, "He said to tell you, that you should do it for the greater good". Harry swore using some of uncle Vernon's choicest swear words, then, much to the paintings misfortune, he set it alight with his wand, watching as the canvas curled and crumbled into a sorry looking pile at the base of the frame. That done, Harry turned around and summoned Hermione's small beaded bag from the guest's room, old habits die hard he muttered darkly to himself. When the bag arrived he scanned its contents quickly making sure in had all the necessities, grabbed the sheet of ruins from the table, then approached the headmasters private Floo and called out Diagon Alley before disappearing in burst of green flames.