Here is the edited/revised final part :-)
September, 1942/Greenroof, 2303
"In the end I was the one who forgot the person I became in Narnia."
The two brothers were sitting atop the hill called Aslan's How, looking down on the lingering devastation of the battle, and though both still wore their battle stained armour, neither seemed to care. Moments for quiet reflection were rare in the wake of battles, and Peter suspected that Edmund would have been content to sit there in silence until Susan appeared to scold them for wandering off. Ordinarily Peter would have let him, but there was far too much to say now—and far too little time to say it.
I've been an utter fool," Peter continued quietly, staring out over the twisted remains of the Telmarine catapults. Edmund didn't seem to see the need to contradict him, and a moment later he continued. "After everything that happened here the first time, I still forgot what was most important."
"Everyone does sometimes." Instead of the anger Peter knew he deserved to hear in his brother's voice there was a quiet understanding. "Well, except maybe Lucy." They both laughed at that, but Peter quickly became serious again—he was not willing to let Edmund keep him from saying what he knew was necessary.
Save it for later. Well, it was later, and neither one of them could avoid what that meant. "Ed, I'm sorry." Somehow that didn't seem nearly good enough though, and he rushed on—desperate to at least attempt fixing what he had so nearly destroyed. "I've been an utter prat, especially to you, and you were brilliant. If it wasn't for you the White Witch would be back right now, and—well, you know."
Edmund sighed, and for the first time Peter saw a hint of the anger he deserved on his brother's face. "I didn't expect you to forget what it cost to defeat her the first time, but then, I suppose you did have it sorted."
Peter winced at Edmund's reference to his foolish words from before. More than anything he wished he could go back and make right his mistakes, but he couldn't—time did not run backwards, and no amount of wishing would undo the last year.
"I didn't realise what I was doing." The excuse sounded pathetic, even to his own ears, and he shook his head, trying to find a better way to say what he meant. "I know that doesn't excuse my actions." Maybe nothing ever will. "I know what it cost the first time, and I can guess what it cost this time. You shouldn't have had to face her again. "
"Am I never to be free of her?" For the first time Edmund turned to face him and Peter nearly wept at the weariness in his eyes. "Will she be there to taunt me everywhere I turn?"
"Never again," Peer promised firmly, though he knew he had no real power to back the decree with. "Never by my foolishness at least. I should have been strong enough to resist and destroyed her as soon as I realised what they were planning. I feel like a traitor; Aslan should never have made me king." The instant he spoke he regretted the words, but Edmund seemed to understand what he meant.
"I was a traitor once; do you think Aslan made a mistake when he crowned me king?" He wasn't angry, at least, he didn't sound angry, but that only made Peter feel worse.
"Of course not!"
"Aslan forgave me, you forgave me, and maybe someday I'll forgive myself—but none of that changes what happened. That's the thing about redemption, Pete; it doesn't undo your actions, it doesn't completely take away the guilt, but it does give you a second chance. Yes, you almost helped resurrect the White Witch, yes you were a complete arse to Caspian, yes you led a raid that allowed far too many Narnians to be slaughtered; but you also defeated Miraz, you showed mercy and wisdom in not killing him, and you led your army to victory in the name of Aslan. We all make mistakes, even High Kings."
Peter stared at him for a moment, not seeing his twelve-year-old brother—instead the Just King of Narnia's long lost Golden Age stared back at him, smiling slightly though his eyes were grave. Edmund had earned his title well, though currently Peter barely felt he deserved justice.
"When did you become so wise?" he asked, only half joking in an attempt to push away the lingering sense of guilt.
Edmund laughed and elbowed him lightly in the ribs, suddenly appearing much closer to his actual age—his English age, at any rate. "Apparently I'm still not wise enough to stop coming to your aid every time you're an idiot."
And if past experience is anything to judge by, you never will be. "I never thanked you properly for helping me at the train station—you shouldn't have you know. You have always been there, and I, well, you know."
Edmund glared at him. "You aren't going to get all sentimental, are you? Susan is bad enough." He wrinkled his nose, looking vaguely disgusted, and Peter couldn't help wondering just what Susan had done this time.
"No," he conceded at last. "I'm not going to be sentimental, but somethings still need saying, and thank you is one of them." He paused, wondering just how much he could say without earning a cross shove from his brother. "And, I'm sorry. I never should have fought in the first place—a true king knows when to walk away." Guilt settled over him again when he as he remembered the disastrous Night Raid—he should have walked away then, while there had still been time.
Edmund's elbow connected with his ribs far less gently this time, and despite the chain mail he still wore Peter scowled and shifted away.
"Ow! Ed!" Was I thinking how wise he was only moments ago? But Peter had long ago accepted the sometimes infuriating contradiction that was his younger brother.
Edmund looked not at all repentant. "Stop that! You can't go back and change it; what is it Aslan always says? We can never know what would have happened? At least now you have a chance to change what will happen."
"You mean when we go back to England?" Peter kept a wary eye on his brother's elbow, and was careful to stay just out of reach—he didn't particularly want any more bruises.
Edmund nodded, looking thoughtful. "You told me once that things didn't have to go back to being exactly as they were before; that's what I'm counting on now. You can choose to be High King Peter, even in England, and that doesn't mean picking fights with boys in train stations."
"I know. I will remember Ed, I promise." Now I just have to apologise to Lucy, Susan, and Caspian.
Edmund grinned and pulled him to his feet. "Now stop moping, you great sap, and let's find something to eat. I'm starving!"
"When are you not starving?"
Edmund shook his head, still grinning, before he seemed to sober as he looked back over the battlefield. "You know, I've rather gotten used to having you hovering around."
Edmund glared at him, daring him to interrupt again. "What I was trying to say is, well, I'm glad Miraz didn't win. I would have missed you." That was all the warning Peter got, before Edmund, who had so recently been scolding him for being sentimental, was hugging him. Peter, however, was far too wise to comment on that fact.
"Right," said Edmund, somewhat hoarsely a moment later. "I'm still starving." He turned to stomp off in the direction of the makeshift camp, stopping to call over his shoulder. "And, Peter, if you tell Susan I hugged you, I'll kill you myself."
Peter grinned. "She won't hear a word about it from me, little brother."
"Younger! How many times do I have to tell you, it's younger brother!" Edmund seemed quite pleased at the chance to continue their longstanding argument.
Peter laughed and raised his hands in defeat. "As you say…little brother." At that point he decided it would be in the best interest of his health to run, and so he did—though his happily infuriated brother made quite a show of chasing after him, shouting dire threats he had no intention of carrying through with.
It felt good to be running past groups of familiar Creatures and breathing Narnian air. It wasn't quite alright—the past year had still happened—but it was better. Peter thought he understood now; it had never been his crown or status that made him a king—it had been his actions. His own actions had not been very kingly of late, but there was time. He could change. He must change, for he did not think he could bear the guilt of betraying the everything he held dear a second time.
I do understand now, he thought, as he dashed round a group of confused Dryads. I understand why Edmund tries so hard, why he always feels it is his duty to protect us, and why he does everything in his power to be just in all things. He failed once, and I have too now. Never again.
He would be a king, he determined then, he would remember and hold on to who he had once been—even if he must return to a land that threatened to make him forget.
Hope the revisions helped.