Susan's drifted. It hurts to admit it, but they all know it's true. She won't believe in Narnia anymore (and that's just it: she won't believe, not she doesn't), not since they left. Leaving Narnia? It hurt them all.
Peter saw it as a new mission, a challenge they had to step up to, finding Aslan in England. (Well that isn't strictly true, Edmund concedes, Peter was too busy wallowing to see it that way at first. It took Edmund, ever Pete's protector, sitting him down and lecturing him, explaining that Peter was their strength and they needed him if they were ever to get through this together. And Pete got it.)
Lucy immersed herself in Narnia initially, her faith in Aslan unwavering, and for a while they had worried that she hadn't fully returned to England. (Edmund had, very gently he thought, explained to Lucy that she was scaring them. That she was their faith and they needed her if they were ever to get through this together. She agreed quickly and settled for living in England.)
Edmund… Well, he loved Narnia. It was home. And yet, for all that it hurt never to return, he can't help feeling that (very deep down, and he is never ever going to say it aloud), honestly, wherever they all were? That is home. They are home. He's never going to take his siblings for granted (not again) and he's determined to make sure they never feel they are being taken for granted (not like he did). He doesn't want this loss to split them up (never again).
And yet… Susan has drifted. Ed blames himself: he had made sure Peter and Lucy were all right, made them live in England, not in memories of Narnia. He had explained they were his strength and his faith and they were needed if they were ever to get through this together. Su had seemed fine: she was living in Narnia and not England, and didn't seem to need to be told she was his wisdom and they needed her if they were ever to get through this together. And Edmund was an idiot! Who is fine when they've lost themselves? When they've been exiled from their home? How could he not have realised that living in England immediately was a danger sign? She was forcing herself to live in England, because the memories of those perfect days in Narnia were too painful to bear. Why didn't he see it before it was too late? She went out more, wore more make up, tried to create enough memories to fill the gaps in her aching heart. Pretended she had never been to Narnia. Peter and Lucy didn't, couldn't, understand. They brought it up continuously, not seeing how each word hurt her, until Susan had snapped. She had called it all a "childish game", not even two weeks ago. Her name still isn't allowed to be mentioned in front of Pete or Lu; it hurts them too much to think of what has happened to their Gentle Queen. They know she's drifted, and they can't bear it. So it goes unspoken of.
Ed tried again, just this morning. He went by her flat. Explained about the plan with the rings (tried to, anyway). Asked her to come get the train with them (begged her to see them off, anyway). He's still holding the spare ticket in his hand as he gazes out of the carriage window, letting the voices of his eldest and youngest siblings wash over him. They don't know he's been to see her. They don't understand. Edmund can't help wishing he didn't understand either. "He's forsaken me, Ed! Forsaken all of us! And I'm sorry, I am, but I simply can't forgive Him for that. And no one seems able to forgive me for feeling like this!" He'd hugged her, tight, and promised that he would always forgive her anything (how could he not?) and reminded her he loved her, they all did. She didn't go to the station, and he wouldn't press her. All Edmund can do is hope she hasn't drifted too far, and he'll be able to undo the damage when they return to London.
"Eddy?" Peter looks concerned, and Edmund realises he's been too quiet for too long.
"Just thinking, Pete. And don't call me that."
He receives the inevitable jibes ("So you can think?" and, "It looked serious… Were you trying to count to ten?") and successfully evades mentioning what he was really thinking on ("No, Lu, I was thinking of cabbages and kings, of course."). Determined not to zone out again, nor think on such gloomy thoughts, he agrees to join in the game of 'I Spy'.
"I spy with my little eye… Oh Aslan, what a dull game!" he laughs, and peers out of the window for an object that isn't completely obvious.
He notices immediately. He can't 'spy' anything, because the scenery is one big blur. They're going far too fast. Far too fast, and up ahead he can see how the train tracks peel off to the left. Oh Aslan. He looks back at his siblings, and they're anxiously watching him.
"You're on edge, Ed. What's wrong?" Peter is leaning in, voice automatically low and tense, and Lucy is wrinkling her brow with worry. Edmund looks at them, his King and Queen, and smiles tightly. He gently brushes a strand of blond hair out of Peter's eyes, and presses a kiss to Lucy's forehead.
"It's probably just me worrying needlessly," because everyone knows Ed feels the need to constantly worry over the safety of his siblings, "But we're going too fast." He starts speaking quickly now, as the bend in the tracks gets ever closer, and both orders and manhandles his siblings in turn.
"Pete. Sit on the floor, yes there in the corner, and brace yourself against the walls. Lucy, sit in his lap. Now, Lu!"
They obey, and Peter wraps his arms around Lucy. Edmund kneels by them, spreads his arms around them, and the world explodes. They each proclaim their love, as the carriage around them twists and burns. In those last frantic seconds, as the train rips itself into pieces and pain races across his back, Edmund thanks Aslan that Su didn't use the spare ticket, still clenched tight in his fist.
Susan had run to the train station, hating to part on such bad terms with her siblings, and was determined to see them off, anyway. She missed the train by less than a minute. Told herself not to cry anymore today. Walked home slowly, let herself remember how close they had been (even… There). By the time she had meandered home, the telephone was ringing. She answered, and had listened for mere seconds before she was crying in earnest again.
The tears have finally dried up, but Susan doesn't think it will last. She's about to see their bodies. As she sees them, her heart goes numb. It's so typical of them: Peter and Edmund, arms locked around each other, with Lucy nestled between, as safe as she could be. Edmund's the most damaged, clearly protecting them to the last, having taken the brunt of the collision. But putting the broken limbs and the shards of metal embedded in her little brother's back aside, their faces are untouched. Tranquil. Susan is sure, for a split second, that they are about to wake up. It's remembering that they never will again that has Susan crying once more. Susan stands there for Aslan knows how long, with her heart encased in ice, wishing she'd accepted Edmund's spare ticket. Wishing she's never drifted so far.