Karen is informed by owl that she's a prefect. She writes her friends about that, of course.
They are not prefects, but are pleased for her!
He scrapes enough money together for the test of the wards on a few square meters outside the house. Voltaic piles work as desired. He spends the rest of the summer camped out there experimenting.
Miranda visits sometimes to help.
She might notice that Minor is vaguely chattier around her and spends more time staring at her.
"Do I have something on my face?"
She snorts and goes back to rearranging his magnetite and amber, erstwhile Christmas presents and now experimental tools.
He is so, so ecstatically happy. And very annoyed when term starts and he has to abandon it for Hogwarts, where none of his experiments will work.
"You're not excited about classes at all?"
"I feel like at this point I can make as much progress at home if I'm willing to frequently bother Michael and Timothy. I am looking forward to seeing my friends more, though."
"I missed you too."
" - but you should've seen what I was in the middle of collecting data on!"
"I bet you have notes!"
He has so so many notes! Indexed searchable notebooks full.
And Miranda has a funny story about how she now has lots of practice at the charms for healing electrocution.
"I didn't want to take it slower!"
"You could wear gloves!"
"I couldn't switch to gloves halfway through the experiment without compromising the scientific integrity of the results!"
"Remember when he got the eels and kept letting them zap him -"
"It was pretty memorable!"
"In a hundred years when electricity is really important you'll agree with me it was worth it!"
"I don't think it was necessary!"
"I guess I could've thought of gloves in advance." He sighs and shakes his head. "O.W.L.s year. Michael says school went by really fast for him but I'm not really seeing it."
"Yeah, it feels like a long time ago we were in first year - d'you think we'd be friends if I hadn't come into your compartment?"
"You and Karen would've probably still ended up friends, right?"
"I didn't even meet her on the train to begin with - I guess we could've met through her, yeah."