Like Sirius, I double down a lot. I started this story with time travel, and I'll be damned if I don't end it that way too.
It's one of my favorite fantasy conceits, after all.
And what's the point of fanfiction if not to explore your favorite things?
One.
Sirius held Peter's shoulders as they both stepped back into the headmaster's office. "Peter," he said, "here's what I need you to do. If things work the way I hope they will, if I win out and things go right, then by the time I get back, we're going to move against him. We're putting an end to this. You knew him. You worked with him, for him. I need you to think, hard, about everything you've ever learned about that man. Everything he ever said to you, anything you've ever heard him say to someone else, the people he's worked with, the people he's manipulated, all of it. Every single thing. No detail is too small."
Peter's brow furrowed. He nodded. "All right."
"I don't need you to fight," Sirius went on. "If things go right, nobody will have to fight. Not conventionally, anyway. All I need from you, all I'm asking, is for you to remember. If you can do that for me, then you're going to help save Wizarding Britain. Anyone who ever thought you didn't belong in Gryffindor is going to have to eat their words."
Peter actually smiled. "Including you?" he asked.
Sirius flashed a familiar grin. "Especially me." He reached out with one hand and pulled Remus close. "If I fuck this up. If I don't come back. The two of you need to look after Harry for me. I have no intention of doing that to you, or to him, but if something goes wrong . . . if I ruin this for everyone . . ."
Remus nodded. "Put it from your mind, Padfoot. Harry will be just fine."
Peter nodded in turn. "Focus on the mission," he said.
Sirius drew in a breath, squeezed his friends' shoulders, and turned. "Caius Labeau," he called out to the empty room. "Kafell, Last Prince of the Summer Court. I have a request for you."
The prince folded into reality and stepped out of the shadows, still in his crisp suit, still with his wild hair. His grin was wide, his eyes sparkling, as he took in the other two. "Aha," he said, approvingly. "You have brought your retinue. Good. Very good." He gestured grandly. "Relay to me your request, Sirius Black, that I may do my utmost."
"Send me to London," Sirius said, "in December of 1926. Before the birth of Tom Marvolo Riddle."
Two.
He walked slowly, with more deliberation than he ever had, focused on his mission. Kafell had sent him back two days before Tom's eventual birth, and his mother's death—the last day of the year—and Sirius used that time to make note of how much the world had changed in sixty years . . . or, rather, how much it wouldn't change. Sirius could tell that he was in London. That much, at least, was reassuring.
It crossed his mind to visit the old home, but of course his grandfather Arcturus would be the master of the house in this era, eagerly awaiting the birth of his father. Sirius didn't suppose it would be too hard to convince his blood-happy predecessors to take in the young heiress to such a historic house as Gaunt. That much would at least provide her with shelter.
But no. Sirius couldn't bring himself to do that.
Not to her, and not to her son.
"Besides," Sirius said to himself, "if the goal is to drive little Tommy away from the Dark Arts, and I think it is . . . having him grow up around my relations would quite possibly be the worst decision I could ever make." He shook his head emphatically. "No, no. Best to keep far away from Islington."
Sirius turned his attention to preparations. He'd asked Kafell to return to him in ten years. He had ten years to facilitate his plan, and two days to start it. He went this way and that, into this shop and that, gathering as much as he could without drawing overmuch attention to himself. Sirius got some looks from proprietors, mostly because he was paying for his goods with solid gold; but, thankfully, there wasn't a merchant in this era or any other, magical or otherwise, who'd turn down gold if offered it.
Mostly, anyway.
So it was that, once he did find a pitiful little woman huddled in a threadbare cloak, pushing against the wind and barely able to keep her feet, belly swollen and hardly covered at all against the elements, Sirius Black was in possession of every conceivable thing he would need, all stuffed into a pack he had slung over one shoulder.
Sirius drew in a breath, squared his shoulders, and walked clean into Merope Gaunt.
"Oh!" he called out, dramatically, and he was sure he sounded like a fool. "Ho, there, missus, are you all right?" He manufactured his tone, hopefully, to sound like he'd just happened to cross Merope's path and wasn't actively searching for her. The last thing this poor woman needed was to think that some witch-hunter—or, perhaps worse, her father or her brother—sent him to track her down.
The mother of Lord Voldemort looked up.
Merope's lips were blue, her teeth chattered, and Sirius realized all at once how dire a situation he'd just landed himself in. "Merlin preserve me," he whispered, not pretending anymore. He put a hand on his companion's arm and started to lead her down the street. "It's all right, now. Just follow me, all right? Come along. You're going to be just fine."
The worst part of it all.
The part that haunted Sirius more than anything he'd seen in all his life, even the bodies of his best friends.
When he looked at this woman's face, when he saw her in the flesh in front of him, Sirius Black didn't see a woman. This wasn't the harbinger of the Wizarding World's most notorious devil. This was no bringer of doom, no dark queen without remorse, no temptress who would force a man into marriage.
Merope Gaunt was a girl.
Merope Gaunt was a child.
And she was destined to die before the dawn of 1927.