Following Sirius and Harry, Tom stepped into the ice cream parlour. The three of them chose a seat by the window.
There were a few other customers scattered around. Wanting a bit of quiet, Tom casually traced a line through the air with his finger. Instantly, the surrounding noise vanished, leaving a pocket of perfect silence around their table.
Sirius's eyes lit up.
"A wandless Silencing Charm? If I'd known that trick at school, I would've charmed half the girls in the castle."
Harry shot him a teasing look. "Didn't you say you were already popular?"
"Of course I was." Sirius straightened proudly. "I received more love letters than James and Remus combined."
The way they spoke did not resemble father and son so much as old friends. Between jokes and banter, Sirius gradually recounted what had happened after his release from Azkaban.
After a brief period of recovery, he had marched straight to Number Four, Privet Drive to see Harry.
The Dursleys had not welcomed a "freak" at their doorstep. The thought of neighbors discovering wizard visitors nearly drove them mad. An explosive argument followed, ending only when Harry dragged Sirius away.
But Sirius returned the next day. And the next. And the next.
Eventually, the Dursleys broke. They agreed he could visit once a week just to restore peace.
Not that it mattered for long.
Sirius soon purchased Number Six, Privet Drive.
Harry felt as though the misery of his first eleven years had been payment for this single stroke of happiness. A short walk to his godfather's home, returning only at night to sleep under the blood protection of the Dursleys' roof. He barely needed to interact with them at all.
In some ways, it felt better than Hogwarts.
Well. It would be equal to Hogwarts if Snape resigned.
They were in Diagon Alley today to order a Firebolt for Harry. He had refused at first, knowing the price must be astronomical. But Sirius, determined to make up for lost years, would not be denied.
As Tom spooned up a scoop of "Unicorn's Dream," he remarked lightly, "I thought you'd have hexed them."
"I did too," Harry admitted. "But he never even drew his wand. If he had, Uncle Vernon wouldn't have dared raise his voice."
"Of course I didn't," Sirius said, ruffling Harry's hair. "They may not treat you warmly, but they've fed you, clothed you, and even take you back every summer. Merlin's beard, after I ran away at sixteen, my mother never came for me again. Every holiday I stayed with James."
"I can see they hate your magic, not you as a person. They didn't want our world, but they still raised you. They're not saints, but they didn't betray you either."
Harry lowered his head thoughtfully.
Tom looked at Sirius with surprise. "You're far more sensible than Professor Snape ever claims."
Sirius froze, teeth grinding. "That greasy git would never say a good word about me. And I still don't understand what the Sorting Hat was thinking, putting you in Slytherin."
Tom sighed dramatically. "Truly tragic. I was born a Hufflepuff."
The look on Sirius's face suggested he wanted to argue that Tom's readiness to escalate any conflict made him a perfect Gryffindor, and Hufflepuff was perhaps the least plausible option imaginable.
But he let it pass.
"Tom, how about I buy you a Firebolt too?" Sirius suddenly suggested. "Call it a small token of thanks. If you ever need anything else, just say the word."
"No need," Tom replied with a smile. "I already have one. If you want to thank me, tell me how you made the Marauder's Map. And perhaps copy the Black family library for me."
"Done." Sirius did not hesitate. "I'll take you to Number Twelve, Grimmauld Place. You can have whatever you want. Take my mother's portrait too, if you fancy."
Harry visibly flinched. He had seen the fury of Walburga Black's portrait. Removing it would be an act of war.
The rest of their time passed with Sirius enthusiastically explaining the Map's creation. Harry lasted only a few minutes before drifting off into a daze, staring out the window. Tom, meanwhile, listened intently, committing overlooked details to memory.
Before parting, Tom said casually, "My shop reopens the day after tomorrow. If you're free, come have a look."
"Your shop?" Harry asked. "What are you selling?"
He had already decided he would buy something. Anything.
"You'll see in the paper tomorrow."
With that, Tom tossed a pinch of special Floo powder into the fireplace and vanished in green flames, returning to Greengrass Manor.
Sirius and Harry exchanged glances.
"He does enjoy mystery," Sirius muttered.
Harry nodded. "He's amazing. Still in school and already running a business."
...
Two days passed in a blur.
For those two days, advertisements for "WhatsApp" flooded the wizarding press. From The Daily Prophet to The Quibbler, every publication in Britain carried bold descriptions of a device that promised real time communication across any distance.
Curiosity spread like wildfire.
On launch day, crowds of witches and wizards flooded Diagon Alley.
Harry and Sirius, having given their word, would not miss it.
They entered through the back of the Leaky Cauldron.
And froze.
Above them, massive floating posters drifted across the sky, emblazoned with shining images of WhatsApp.