Disclaimer: Harry Potter belongs to J. K. Rowling and all those people usually mentioned in disclaimers, like Scholastic Books and Bloomsbury and Warner Bros. and... well, point is, not to me. I don't own Harry Potter. I don't make any money off writing fanfiction.

Pairings: none, except James/Lily in the background

A/N: The title is taken from Rufus Wainwright's rendition of "Across the Universe." I have read many dimension travel fics, so I expect them to have influenced my writing. I do hope, however, that I am not plagiarising anyone. Reviews are very much appreciated and constructive criticism is welcome, especially since this work has seen no beta.

xXxXxXx

James pours Firewhiskey into two glasses and sits down on the couch, extending one tumbler towards his unbidden, but not entirely unwelcome guest.

It is the only thing they can do under the circumstances, really. James's head swims. Inter-dimensional travel. A young man, claiming to be Harry Potter, refusing to believe in James's or Lily's existence. His eldest son, alive, although he had been killed on Halloween, 1981. Dumbledore's frown. Amazement in Lily's brilliant eyes. And hope. Hope that this is somehow his son, returned to him, through a miracle.

Only it isn't his son at all. Harry – might as well call him by his given name – gracefully accepts the whiskey and sips with the air of a person who's drunk a lot of this stuff. He's got trademark messy hair, Lily's green eyes, but he's thin, with premature stress lines and an unfriendly disposition. Bespectacled eyes too guarded for a boy of his age, reflexes too honed. This boy isn't at all like Aaron, his and Lily's fourteen year old child. They surely look alike, except that Aaron's eyes are hazel, but Aaron is wilful, smiling, careless and free, the way James and Sirius had been at school. Harry reminds James of Mad-Eye Moody, if anyone at all.

Whoever has been taking care of him in James's stead, they haven't done a very good job.

His son – but not his son – but yet his son – isn't in a hurry to start a conversation, so James thinks over what to say. Questions about Harry's life seem a tad too personal, whether or not Harry is supposed to be his eldest son.

Son and heir.

"So you are eighteen, then?" James asks, opting for a neutral question to start with.

Harry simply nods.

"Dumbledore says our timelines must have diverged on Halloween, 1981. When in your dimension, Lily and I… in this dimension, it was you who…"

"Died," Harry finishes, seemingly with no qualms when talking about death. "Which might be a good thing."

"How dare you!" James erupts immediately, stung by such a cavalier approach to a subject that still brings tears to his and Lily's eyes, after all these years.

"Your world is happier," Harry points out, unfazed. "Neville seems to be doing a good job of being the Boy-Who-Lived."

His voice is strangely monotonous.

"And you weren't?" James asks.

Harry's mouth twists into a smile that looks so ugly it could belong to Snape.

"In my own way, I was absolutely fantastic."

James stares at this boy-man in front of him and suddenly realizes that he doesn't understand. He doesn't talk to people like this, in strange half-clipped phrases, loaded with meanings, masking some things and saying others bluntly. James is open in expressing his emotions, and appropriately silent on topics of death, destruction and Voldemort. Not that he doesn't have strong feelings about Voldemort. Still, it's a conversation for the Order, for adults. He gets a strange feeling that he and this boy are speaking different languages.

He is almost glad when the Order convenes to discuss the situation. He feels awkward sitting with this boy one on one. He is an Auror, a professional and an adult, and yet he finds himself oddly lacking in something important when dealing with this strange boy who is and is not his son.

Predictably, Mad-Eye Moody and Snape are the two Order members most suspicious of Harry's presence, but Harry doesn't seem to mind. In fact, the corner of his mouth quirks up in what could be called a smile. Harry steadily avoids looking at James, Lily or Sirius. Lily is distraught by the treatment, James can tell, and yet Lily hasn't spent an hour in the boy's company, trying to make conversation. If she had, maybe she would understand that this would not be the happy ending they were all wishing for. James is at once outraged that Harry is ignoring his mother and glad that he doesn't pretend everything would be okay.

With a person like this, nothing could possibly be okay at once.

"Another Potter," Snape sneers. "As if there weren't enough already."

"I'm told I've been missing from the original count, sir," Harry says without batting an eyelash.

James doesn't like it that his son calls Snape 'sir', although Snivellus has grown up to be a Professor. It just doesn't feel right for a Potter to defer to a Snape.

"As arrogant as your father, I see," Snape continues, glaring at the younger man, and James bristles.

"I'm hurt that you would expect anything different, sir," Harry shrugs, giving the Professor a mean-looking smile.

Suddenly, for a second, he and Snape look more alike than he and James do. It's in the air of casual spitefulness, which both of them pull off unsettlingly well. For the first time, James thinks that Harry might be a formidable opponent.

The brief exchange of pleasantries is over and the meeting starts in earnest. Neville Longbottom is gazing at Harry with undisguised curiosity, eyes glued to the scar on Harry's forehead. Dumbledore debriefs the Order on Harry's appearance in their dimension and his status as the Boy-Who-Lived in the one he'd come from, and Harry seems uncomfortable under everyone's scrutiny, although he's holding up well. Probably used to the attention, James thinks, recalling the stares Neville has received throughout his life. To think that his son would have to go through with what Neville has had to – no. This is not really his son, but this thought doesn't help.

By the look of Lily, this thought doesn't help her, either.

Harry doesn't speak until he's addressed directly and then he is laconic. As a former Boy-Who-Lived, he doesn't have any advice for them. Yes, in his dimension, the struggle against Voldemort is now over, but the price is hardly worth it. There's been a war. They, here, are holding up much better so far. Harry has no tips to share and nothing to advise them on. Except that, later, of course he will. It's in the little comments – his shocked 'Neville hasn't learnt Occlumency?' and 'What do you mean you haven't started hunting for Horcruxes?' Each time, Harry will look at them as if finding it strange that obscure mind techniques and horrendously evil objects are not part of their daily existence. Today, it will not come up, not yet. Today, they have only begun to scratch the surface of the differences between the two dimensions.

Harry's world seems like a hellish scenario of what would have happened had Neville actually won the Triwizard Tournament in his fourth year. Neville looks conflicted and James understands why. On the one hand, Neville has had advice whispered into his ear the entire time by the same person as Harry, but he hadn't won the Tournament even with that help. On the other, by not winning, he'd thwarted Voldemort's plans and delayed his return.

Sirius, James notices, has been gazing at Harry throughout the meeting, as if trying and failing to decipher a puzzle. Sirius would have been Harry's godfather, had Harry lived. Harry is here, now, and Sirius takes a measure of him, of what he would have been like, but it's an exercise in futility. Harry, his Harry, would have been very different from this war-hardened, sharp-eyed creature.

xXxXxXx

Over the next few weeks, James discovers that Harry doesn't like to be touched; Lily nearly bursts out crying at the implications. They also learn that he doesn't eat a lot for a boy his age and doesn't talk much, definitely never blabbering on about girls and Quidditch and whatever else is usually on the boys' minds. He does not miss his home dimension or else he never says he does. James notices thin scars on Harry's wrists and aches to ask, but for the longest time doesn't, since it's not his place and Harry's about as approachable as Snape. Then again, he muses, if it's not his parents' place, then who else is going to ask – so he corners Harry once to get at least one answer.

"That Adava Kedavra you said transported you here – who hit you with it?"

Harry frowns.

"Does it matter?"

"Yes," James presses, because Adava Kedavra is meant to kill, irreversibly. It hadn't worked on Harry and Neville in their respective dimensions because their mothers died to protect them, but nobody should be thrown into a different dimension with this curse. The only way it's never been tested –

"Fine," Harry rolls his eyes. "I hit myself with it, alright? The war was over, Voldemort died earlier the same day, I'd served my purpose. Whatever tipped you off?"

"Logic," James says in a strangled voice. "And your wrists."

Harry glances down and smoothes a finger over one jagged scar.

"Good investigation skills. Happy now?"

"No," James whispers, because otherwise he would have to shout and reprimand Harry for his attitude, like he would do with Aaron, but he feels out of his depth here.

Harry doesn't bring it up ever again and neither does James. He doesn't inform Lily, either; he finds there is a lot he doesn't say to Lily about Harry, generally. He suspects, however, that she sees things before he does. She is almost constantly on edge, alternating between radiant joy at Harry's return and sadness at the way Harry has grown up to be. James feels for her and says so, but he knows it's not enough; and it jars him that he and Aaron aren't enough to make Lily smile anymore, but Lily and Aaron aren't enough to make him smile either, these days, so who is he to protest?

Besides, it's so difficult to balance attempts to incorporate Harry into the family with not pushing Aaron away. Aaron, home for Christmas, has taken Harry's appearance as a personal affront, it seems; the idea of an elder brother offends him for no reason James can discern. Such attitude is especially bizarre since Harry makes no effort to usurp Aaron's place, holding himself aloof. James lives in the constant expectation of a scandal between the two brothers – Aaron has never been good at being denied anything – and when it comes, it is of course Aaron who starts it.

"I don't want you to be here!" he shouts one day in the library and James is about to intervene from where he's standing in the doorway, but he is interested to see how Harry will handle this.

"Well, that is very unfortunate, isn't it," Harry answers dryly.

"I hate you! Everything was fine until you came! I want you to leave!"

"I cannot fathom the depth of your angst-" Harry raises an eyebrow in a very Snape-like fashion.

Aaron tries to shout at the older boy some more, but sees that his hysterical demands are having absolutely no impact, so in a flurry of motion he throws himself at Harry and tries to pound him with his fists.

"Leave! I want you to leave! They won't love me anymore once you're here – you can't just come back here, you're dead, I don't want you here, I want everything to be like always – "

Harry looks nonplussed and for a second James is worried that he will hurt the younger boy, but Harry does no such thing, only holds Aaron in place, preventing him from pummelling Harry with his fists – and suddenly, a dam bursts and, to James's amazement, Aaron is sobbing into Harry's shirt, still sprouting threats and demands. Harry sighs and puts his arms around the younger boy, looking extremely uncomfortable.

"Don't worry," he says, once he deems Aaron more likely to comprehend him. "I have no intention of stealing your parents away from you."

"Aren't they your parents, too?" Aaron asks and hiccups.

"Not… entirely. I never knew them. I don't really belong here. You have nothing to fear from me."

Aaron draws away and frowns.

"Don't you want to get to know them?"

James is holding his breath now, feeling as if half of his existence is hinging on Harry's response.

Harry doesn't reply at once.

"There was a time when I wanted it more than anything else in the world," Harry says softly. "I'm afraid it's a little too late."

James's heart clenches at the finality in Harry's voice, but Aaron only frowns deeper.

"You're here now. You can get to know them now. I know they want to know you – you are being unfair to them! And I don't believe that you don't care about them – if I'd grown up alone…" Aaron swallows, his Adam's apple bobbing painfully. Clearly, such a scenario is too difficult for him to contemplate.

Harry cocks an eyebrow at the younger boy.

"I thought you've just spent half an hour demanding that I leave?"

Aaron flushes, but doesn't give in.

"I – you're here now, aren't you? I just – if you were going to – if they wouldn't care about me anymore – that's one thing, but you can't just ignore them – it's not fair!"

"You must be a Gryffindor," Harry says, looking bemused.

"Of course," Aaron nods. "Weren't you?"

"Yeah," Harry runs his hand through his hair, a gesture James knows so well because it's his, too, when he's nervous or upset or doesn't know what to say, and he continues to look in on his two boys intently, hoping for – he doesn't know if it's possible, but he's still hoping –

"I heard you're a Seeker. You can fly with me. You can help me with my homework. You can teach me fun spells. You can tell me about – things…" Aaron is looking at the floor and then, drawing a shuddering breath, he raises his eyes. "You know. I've always wondered what it would be like if you were alive and I had an older brother. And I can tell you about mum and dad. You can't just not care. I'll make you care. I don't want a brother who doesn't care."

Harry is looking at Aaron is if the boy has sprouted hoofs and wings, clearly unsure how to react, and James is equally astonished. It is so bizarre that it is Aaron, so fiercely opposed to Harry's very presence at Godric's Hollow, who finds a way to crack the barrier erected between Harry and the rest of the world. Aaron, who understands least about war and loss and Harry's attempted suicides. Maybe it's because he understands least that he finds the daring to push through, to disregard Harry's defences. Aaron is a Gryffindor on a quest – and he manages admirably. He makes Harry participate in conversations at meals, even if Harry only grunts in response. He makes Harry go out into the yard and fly with him. He badgers Harry with questions about the other dimension and homework and spells and – and James even hears Harry laugh, once. James privately thinks that the experience has been good for Aaron, too; to feel capable of doing something meaningful, to find a new place within the family, a place where he can do most good and not just get everything on a silver platter, like it had tended to be in the past.

xXxXxXx

"Would you like to join the Order here, Harry?" Dumbledore asks at another meeting, peering at the young man over the rim of his half-moon glasses.

Harry's gaze is guarded.

"I've had enough of the war," he says, "but if you need me, then of course. I don't mean to sound callous, but at least you have your own Boy-Who-Lived."

Neville winces.

"Oh, naturally," Snape rolls his eyes. "Your celebrity lives are so much more difficult than those of us, mere mortals."

"Glad you think so, Professor," Harry smirks.

Thankfully, there is not much work for Harry to do. When asked what he is thinking of doing with his life, Harry surprises everyone by saying he would like to try his hand at Healing. Lily looks well pleased. James is at once upset that Harry doesn't want to be an Auror and understands why. Dumbledore twinkles merrily and says that having their own Healer in the Order would be invaluable indeed, seeing as Poppy Pomfrey is loyal, but to Hogwarts rather than to the Order.

James talks about this idea to Harry when they get home, revelling in the surrealism of discussing his eldest son's career.

"We can go to St. Mungos on Monday, before I continue on to the Ministry," James suggests, hoping Harry will agree.

James wants to help, in any way he can.

Harry nods.

"Thanks..."

James almost thinks Harry is about to say 'thanks, Dad', but the words never actually cross Harry's lips. The more time passes, the more desperate James is to hear them. It is somehow important that his son who has never known him would be willing to acknowledge him as father. Would approve of him. Would not be disappointed in him now that they've met in the flesh. James wonders whether Harry feels the same way, too. Whether he feels worried about being so different from James and Aaron. Harry is definitely not what James would have expected to see in his eldest son, but he is by no means a disappointment. Harry is, perhaps, one of the strongest people James knows. One of the most difficult, too. James admires Harry's self-reliance and quiet fortitude and despairs of it at the same time.

He's only eighteen. Sometimes James just wants to wrap his arms around Harry and dispel his worries, but he knows that the younger man will not allow that.

Someone else has raised him not to allow that.

"Who brought you up?" James asks Harry that evening, unable to help himself.

Harry's shoulders tighten immediately, but he doesn't turn away from the window he's been looking out of.

"Why do you ask?"

Because I'm your blasted father, James thinks furiously, but doesn't voice that thought. Because I care. Because I want to know whom to blame.

"Please, Harry," James says and he knows he sounds tired. "I'm not asking you to tell me anything else. I would be glad if you did, but it's your choice. I'm only asking who raised you."

"It was fine," Harry replies defensively, shoulders still tense and back still turned to James.

If James ever needed a confirmation that it was not fine, this is it, but he already knows that, what with Harry's aversion to contact, surprise at the smallest of kind gestures… It's as if nobody's ever made breakfast for him before. As if everything in his life, from the mundane to the momentous, has been a struggle.

"I'm not saying it wasn't fine. Harry – who?"

Harry seems to take a deep breath.

"Vernon and Petunia Dursley," he admits softly.

James's heart stops momentarily. It is with great difficulty he refrains from ranting and raving – and that only because he knows that this is not what Harry needs to hear. He waits until he gets his breathing under control – although the beast inside his chest is still calling for blood – and squeezes Harry's shoulder.

"Thank you for telling me."

Harry nods, still not looking at him. James has a sudden epiphany that Harry is ashamed. As if it's his fault that… Rage clouds James's vision for a moment, but he struggles to restrain his emotions, this once. He tilts Harry's chin up and forces him to lock gazes with James. Harry's eyes are shadowed, so like and unlike Lily's at once.

"We've celebrated your birthday every year," James finds it important to tell this to Harry right now. "It was never a happy event, of course, but it never stopped mattering. You never stopped mattering. And you never will."

Harry lowers his eyes again and looks unexpectedly vulnerable. He looks eighteen for once. James ruffles Harry's hair – Harry's shorter than he is, which makes it possible without being awkward – and steps away again.

He feels like a huge bridge has been crossed, although outwardly, nothing really changes.

xXxXxXx

And gradually, Lily's eyes fill with hope, again, hope to find what has been lost not once, but nearly twice. Sirius doesn't talk to Harry much, but at least Harry's stopped looking pained every time he sees his godfather. Remus and Harry don't converse much either, but Harry smiles at him these days. Snape and Harry have an odd half-rapport, half-animosity, which isn't like Snape's relationship with any of the Marauders, but Harry is different, and even Snape is forced to accept that he is different, and James never comes to Harry's rescue when they argue, because they perfect it into an art, both fast and snappy and cutting. Neville and Harry compare experiences and it turns out that things are very different for them, but in some ways the same, and Neville seems to revel in the knowledge that someone understands – and they, the adults, the Order, suddenly realise that they've never quite seen the extent to which they didn't understand Neville. And of course Harry is still impossibly jaded and painfully cynical and reclusive, and there are still wounds he has that they don't know of and might never learn of, but at least a part of him is beginning to heal, and James prays and waits and life goes on. And one day, James puts his hand on Harry's shoulder and Harry doesn't flinch, but only smiles at him, and James feels that, at least for now, it might just be enough.