There is an indefinable difference between England and Narnia. When Edmund tries to describe it, he comes up with meaningless words. The air is different, he says to Lucy once, like breathing means more in Narnia than it does here. She nods and says she knows what he means. Narnia is brighter somehow, he tells Susan as they curl up over books in the library, all gold and royal-bright. She smiles and closes her book, stroking the spine (it's Mallory again, one of her favorites now) and just nods, not having to say anything. Everything is more real in Narnia, he tells Peter late at night after he dreams of Narnia again, memories there are stronger. Peter nods once, and Edmund knows that Peter feels the difference more keenly than any of them all, maybe even more than Lucy does.
It's not just the way they are different, though. Sometimes it's the way they can be so similar that makes his throat catch. Sometimes he goes to sleep in the woods behind the Professor's house and wakes up in Narnia for a few blissful seconds until he realizes he isn't (the sun isn't golden enough, and the trees are still and silent around him, because in England they've forgotten how to dance). Later, when he's back in the city, he can't decide whether it's worse being in Narnia for even two seconds no matter how much it hurts afterwards or going for days and days without catching the merest glimpse of Narnia. Some days he thinks it was worse seeing Narnia; some days, when his feet are sore from pavement and everything about him feels lopsided and upside down and the sky has been gray for days, he wishes that he could just see Narnia once more, no matter how painful.
Once he even finds himself wishing, after a particularly long stretch of dreamless nights, that the dreams would come back, though they're never good dreams. In his dreams he remembers the things about Narnia he wishes he could forget (he remembers how to watch Peter die, and see Lucy's golden hair mat with blood, and to see Susan shoot to kill because blood and smoke is all that's left in the world for that moment). No matter how awful the dreams are, though, they're the only thing that he has left of Narnia. (The rest of the time, when he wakes up and Peter's the only thing that keeps him from drowning in the sheer dark of the world, he wishes with every fiber of his being that they would stop.)
He doesn't realize at first how he had started to avoid making new acquaintances at school until his roommate James bluntly points it out, and then he can't even explain why because he doesn't know himself. It isn't until later, as he's suffering through an introduction that he reluctantly allowed James to perform, that he remembers why. Strangers ask questions, like "Where are you from?" and "Where'd you get that scar?" (Edmund knows every scar on his body like he knows the back of his hand - only a few came through the wardrobe with him, and he's kept them to himself, like a book he can read Narnia on) that Edmund can't answer without feeling like he's lying, and he's the Just King, and lying does not become a king. It's like a raw itch that he can't find and can hardly control, and several times his tongue almost betrays him, almost says Narnia instead of Finchley, or oh, that was against the giants in the North the first time instead of the more mundane answer he ran into a stick (it's almost true, but the stick was held by a giant, and was closer to a tree than a stick).
He can tell the other boy is curious, and he feels bitter and angry for a moment, because the Pevensie brothers have become the school oddity because of the way they've changed over summer break. Sometimes after an especially long night when it feels like half the school is staring at him and his throat is hoarse and raw from screaming, he wants to stand up and scream more because he's so damn frustrated (at himself, if he'd admit the truth, but he's lying to himself now), feels like some sort of caged animal, feels remarkably like he imagines the Lapsed Bear of Stormness must have felt after Corin boxed it (33 rounds without a referee and only the mountains to see, but it had been practically legend in Narnia). And as the first months of term slip by he finds himself walking hunched over in the hallways, pretending he can't feel the eyes on his back (where he once came from he'd never minded, but that was when he was a king and he's not anymore).
James prods and pokes him one day into eating lunch with his group, and Edmund relaxes long enough to enjoy it for a moment, until one of the boys leans back and says casually So Pevensie, where do you call home? And Edmund freezes just long enough to call everyone's attention at the table towards him. He almost says Finchley, but the idea of lying again makes him feel ill, and he gets up, mumbling his excuses and avoiding eye contact as he grabs bag and takes off, his back ramrod straight for once because he's angry, angrier than he's ever felt in this English life of his and he can't even place why (it should have been such a simple question), and he can feel the table's eyes on him and he comes so close to turning around and saying A place called Narnia, where I was king once, but he doesn't (he's not king anymore, after all).
When the school introduces fencing halfway through the term, he goes. For a moment when he grasps the foil in his hands the lopsided world stands upright again and he breathes and straightens, and even when the feeling goes away he can still see Narnia. He doesn't fight like the other boys do, hesitant stepping and timid parrying, and he doesn't fight like Peter does, because Peter makes himself into a weapon and Edmund isn't as strong as Peter is. He fights the way King Edmund the Just did in another world so long ago, using the other boy's weight against them and finding his own way to victory (he had never been one for the rules when it came to fighting, perhaps because he had spent most of his time administering justice and upkeeping the laws).
He and Peter are easily the best in the club and when they fight the whole school watches, another mark to chalk up on the board of how extraordinarily strange the Pevensies have become. But this time Edmund doesn't care, because it's just King Edmund and King Peter and if he moves quickly enough and doesn't watch the sidelines, he can pretend that it's Lucy and Susan and the court at Cair Paravel watching them and cheering them on, making bets on who will win this bout.
When he puts the foil away, his hand lingers on it for a moment before he turns to face the boys crowding around him, and for once they don't ask questions immediately, just congratulate him and laugh and say how he's done their class proud. It's a small victory, one King Edmund would have passed over. But King Edmund had treaties to make and countries to consider, and Edmund Pevensie only has this school, so he lets himself be proud too.