Mother mentioned that you sent a Hogwarts representative to Lily Potter (then Lily Evans) in order to demonstrate to her family that magic was real, and, I presume, help Lily obtain her school materials. If you could do this for my own family it would be extremely helpful.
Sincerely,
Harry James Potter-Evans-Verres.
Harry added their current address, then folded up the letter and put it in an envelope, which he addressed to Hogwarts. Further consideration led him to obtain a candle and drip wax onto the flap of the envelope, into which, using a penknife's tip, he impressed the initials H.J.P.E.V. If he was going to descend into this madness, he was going to do it with style.
Then he opened his door and went back downstairs. His father was sitting in the living-room and reading a book of higher maths to show how smart he was; and his mother was in the kitchen preparing one of his father's favourite meals to show how loving she was. It didn't look like they were talking to one another at all. As scary as arguments could be, not arguing was somehow much worse.
"Mum," Harry said into the unnerving silence, "I'm going to test the hypothesis. According to your theory, how do I send an owl to Hogwarts?"
His mother turned from the kitchen sink to stare at him, looking shocked. "I - I don't know, I think you just have to own a magic owl."
That should've sounded highly suspicious, oh, so there's no way to test your theory then, but the peculiar certainty in Harry seemed willing to stick its neck out even further.
"Well, the letter got here somehow," Harry said, "so I'll just wave it around outside and call 'letter for Hogwarts!' and see if an owl picks it up. Dad, do you want to come and watch?"
His father shook his head minutely and kept on reading. Of course, Harry thought to himself. Magic was a disgraceful thing that only stupid people believed in; if his father went so far as to test the hypothesis, or even watch it being tested, that would feel like associating himself with that...
Only as Harry stumped out the back door, into the back garden, did it occur to him that if an owl did come down and snatch the letter, he was going to have some trouble telling Dad about it.
But - well - that can't really happen, can it? No matter what my brain seems to believe. If an owl really comes down and grabs this envelope, I'm going to have worries a lot more important than what Dad thinks.
Harry took a deep breath, and raised the envelope into the air.
He swallowed.
Calling out Letter for Hogwarts! while holding an envelope high in the air in the middle of your own back garden was... actually pretty embarrassing, now that he thought about it.
No. I'm better than Dad. I will use the scientific method even if it makes me feel stupid.
"Letter -" Harry said, but it actually came out as more of a whispered croak.
Harry steeled his will, and shouted into the empty sky, "Letter for Hogwarts! Can I get an owl?"
"Harry?" asked a bemused woman's voice, one of the neighbours.
Harry pulled down his hand like it was on fire and hid the envelope behind his back like it was drug money. His whole face was hot with shame.
An old woman's face peered out from above the neighbouring fence, grizzled grey hair escaping from her hairnet. Mrs. Figg, the occasional babysitter. "What are you doing, Harry?"
"Nothing," Harry said in a strangled voice. "Just - testing a really silly theory -"
"Did you get your acceptance letter from Hogwarts?"
Harry froze in place.
"Yes," Harry's lips said a little while later. "I got a letter from Hogwarts. They say they want my owl by the 31st of July, but -"
"But you don't have an owl. Poor dear! I can't imagine what someone must have been thinking, sending you just the standard letter."
A wrinkled arm stretched out over the fence, and opened an expectant hand. Hardly even thinking at this point, Harry gave over his envelope.
"Just leave it to me, dear," said Mrs. Figg, "and in a jiffy or two I'll have someone over."
And her face disappeared from over the fence.
There was a long silence in the garden.
Then a boy's voice said, calmly and quietly, "What."
"Now, just to be clear," Harry said, "if the professor does levitate you, Dad, when you know you haven't been attached to any wires, that's going to be sufficient evidence. You're not going to turn around and say that it's a magician's trick. That wouldn't be fair play. If you feel that way, you should say so now, and we can figure out a different experiment instead."
Harry's father, Professor Michael Verres-Evans, rolled his eyes. "Yes, Harry."
"And you, Mum, your theory says that the professor should be able to do this, and if that doesn't happen, you'll admit you're mistaken. Nothing about how magic doesn't work when people are sceptical of it, or anything like that."
Deputy Headmistress Minerva McGonagall was watching Harry with a bemused expression. She looked quite witchy in her black robes and pointed hat, but when she spoke she sounded formal and Scottish, which didn't go together with the look at all. At first glance she looked like someone who ought to cackle and put babies into cauldrons, but the whole effect was ruined as soon as she opened her mouth. "Is that sufficient, Mr. Potter?" she said. "Shall I go ahead and demonstrate?"
"Sufficient? Probably not," Harry said. "But at least it will help. Go ahead, Deputy Headmistress."