Basically, a subversion of the whole "contract enslavement" trope seen in the fandom.

I've been drinking and am on painkillers, so this may be a bit disjointed, but I hope the trope subversion comes across right?

While seeking to find ways of helping Harry, Hermione finds an obscure bit of magic from a looted Restricted Section book that (she incorrectly translated because she's a sixteen year old girl, not a fucking professor of ancient languages) mentions "lending one's strength to another".

Yeah, it was actually an old way of basically putting another person into bondage (no, not the sexual kind you deviants, heh, but the financial/obligation kind when there's a debt), and in return for services rendered, the "owner" basically picks up the "servant's" debts and obligations (think vassals and such) as their own -- Mutual benefit.

Unfortunately, she also never implemented any of the safeguards meant to stop the spell from going awry.

Immediately realizing this afterwards as Hermione finds herself bound to Ron, they all panic and quickly seek out a solution in the book -- And then collectively sigh in relief, as both parties need to consent to end the "contract". Ron promptly releases Hermione by their simultaneously muttering a termination phrase to the agreement.

Harry jokingly says that Ron just married and then divorced Hermuone, causing the two to go beet red. However, he then realizes something and nervously asks that if Hermione was bound to Ron... then who was bound to him?

Yeah, outside the abandoned classroom they commandeered, Daphne Greengrass was innocuously walking back to the Slytherin dorms when she was snagged, as she was the closest witch.

The thing about the Greengrasses is that they are dirt poor, like the Weasleys -- However, as they had the "right views", their lack of wealth was easily overlooked by the more prejudiced members of wizarding society, unlike the Weasleys.

Daphne and her family were worried about how they were going to afford both Daphne and Astoria's school supplies and other necessities, even with Daphne doing as much as she could to help out, like handing down her clothes and such that were now too small for her, or picking up a part-time job during her Hogsmeade days and sending the money back.

As she was worrying about that and her sister's temperamental health, she's promptly snagged by the spell, and she finds herself compelled to enter the classroom to meet a gobsmacked and horrified H, R, and Hr.

After explaining things and apologizing to her, Harry tries to release her... But a thoughtful and cunning Daphne doesn't say the release phrase. She doesn't want to be released.

With Harry basically now taking over for her well-being, her expenses, et cetera, her family now has all the resources that would have been split between her and Astoria to be focused solely on her sister.

It also means that she herself would be taken care of. She basically just had the jackpot smack her upside the head. Hell, if she could somehow become his girlfriend and wife sometime in the future, that'd mean security not only for her but her family, too (in return, she'd happily give him the family he's always wanted, and would be a faithful and dutiful partner).

Harry is now stuck with a willing and ambitious "servant" that happily does things like bring him his food, tries to do his washing, help him/do his homework, et cetera (which may lead to an amusing subplot where she fights against the house elves to do such chores), in exchange for Harry buying things that she needs (or giving her the money so she can herself, like a few galleons a month).

...Harry himself is torn after learning why she's perfectly fine with this arrangement, since he doesn't want a bloody maid.

This sort of popped into my brain after thinking about common tropes, and how to subvert said tropes.