A/N: All is Rowling's. Some spoilers for Deathly Hallows, naturally. Tonks/Lupin/Black is my submarine of choice, as should also be fairly obvious, I suppose...
The first thing she saw in the mist was Remus, lying just barely out of arm's reach. His face looked calmer and less careworn than she had seen it in a long while, and it was not without a little reluctance that she moved closer and brushed his shoulder. They sat up, cradling each other and checking for injuries. Surprisingly, there were none to find. Well, perhaps that was not too surprising. Tonks thought she remembered a thin green stream of light heading directly towards her from Bellatrix's wand…
Peering into the fog, more of it seemed to resolve itself into people: Order members, Hogsmeade homeowners, and so many students… Fred waved jauntily towards them, a young, wide-eyed blond boy in a Gryffindor nightshirt tucked under one arm. That would be Fred, all right, not letting even death stop him from doing his business: selling jokes and looking after kids.
Out of the far end of the uncertain surroundings emerged the sounds of a whistle, followed not long afterwards by a train. "All aboard that's coming aboard," came a familiar voice, although it certainly wasn't the engineer of the Hogwarts Express.
"Depends. Just how boring is it out there, Sirius?" Remus called.
"Well, you surely don't believe that I'd be taking the trouble of running the train if things were exciting now, do you, Moony?" Black, too, looked more at peace than his cousin remembered him. He looked good.
"We'll take it, then!" Tonks declared, stepping forward at her husband's side. Sirius was quickly tangled in a three-way bearhug as the rest of the newly dead boarded the train.
"Not that I begrudge you two time with your boy or Harry, or that I want Wormtail running loose amongst them, but I almost wish that you'd gotten here before Pete, Remus. He really did seem repentant once Prongs and Lily and I had had a go at him. I showed him what dogs and wolves generally do to little rats, but you don't catch Animagusness. Speaking of which, how's little Teddy taking the Furry Little Problem? Ted's told me as much as he could, but he went before the first full moon…" Black wandered off expectantly, raising eyebrows at the two in his arms.
"His hair turned gray, his eyes went yellow, and he kept trying to crawl out of his crib, looking for his Daddy," Tonks replied brightly, kissing Remus's cheek. "Perfectly normal for healthy, curious little Metamorphagus."
Sirius threw his head back and laughed. "Makes you wonder if there isn't a little werewolf in us, that led to your talent. Wouldn't that just shock my mum?"
"She'd blame it on my dad's side, of course," Tonks said, looking towards Remus. He looked a little nervous at the turn of conversation to their still-living child, but proud all the same.
"But that would be giving the Tonkses more claim to magic than they've taken credit for, and then where's the point in blasting your mother off the family tree?" Lupin added with quiet, deadpan logic.
"Well, we can't have poor Teddy worrying about unwanted relatives," Tonks said in matching tones. "The good ones still on that tree are already gone." Sirius kissed her firmly on the mouth. Remus raised an eyebrow, and both cousins turned their lips to him.
"What about wanted relatives?" Lupin asked softly sometime later, as the train moved sightlessly through the fog.
"He'll have my mum. And Madame Longbottom'll probably be able to give her some good advice, as long as Mum doesn't start asking about fashonable hats. And Harry's his godfather; he'll look after him."
"I'm surprised you both went out there, with such a little one waiting." Sirius said slowly. At the penitent look in Lupin's eyes, he hastily added, "Suicidally stupid moves are my specialty, remember?"
"Yeah, but Voldemort and Bellatrix were still out there. I don't know how Lily Potter did what she did, and I certainly didn't know how to do it for all those other kids who didn't have the chance to be near their mothers," Tonks glanced once more towards the young students peering curiously into the mist. Surely, they could not all have been of age…
Her husband squeezed her against him once more. "Like godfather, like godson, with any luck, right?" Remus said, partially reassured.
"What, prone to getting in trouble for his stupid foolhardiness masquerading as Gryffindor bravery?" Harry's own godfather asked.
"And taking up with the wierdest friends…" the werewolf finished for him. "You know, I think I'm actually looking forward to sitting down for a nice long chat with Peter, as well as James and Lily. Scabbers got to see more of Harry's first two years."
"You'll at least show him some teeth, won't you, Moony? I was really looking forward to that." Sirius sounded rather like a young boy deprived of cruel entertainment. Like them or not, her cousin was a Black. "Oh, and Snivellus is here, too. He says he regrets nothing, but Lily says he'll come around, sooner or later."
"He's not so bad if you quit baiting him, Pads," Remus said. "Besides, he kept Harry and Teddy alive, so I don't know how much I regret Severus's life, either."
Not long after the train left, another woman arrived in the foggy whiteness, waiting for something. Her heavy-lidded eyes searched for the source of a half-heard cry. She thought she saw it once, but it disappeared before she could reach it. Finally, it appeared under the shadow of a heretofore-unseen bench, waving its tiny pale fists in fear and anger. Delicately, she lifted the bundle, holding it to her breast.
"I gave this up for you," she said in a harsh, haughty voice, no less proud for the surety it now lacked. "I never expected my own. My Lord rewards me as always for my service."
Bellatrix sat down on the bench, beginning the long, long wait for the train. The infant cried on, unseeing, unhearing, unfeeling.