This is…really breath-stopping; this is storytelling of an incredible calibre. I'm not even sure I can describe the effect it had on me. It's as if you've created a path that touches the fictional on one side and the real world on the other, and Petunia has stepped out onto this makeshift in-between place, astonishingly visible. Everything we know about her is dissolving and being remade before our eyes, and her fragility, the slow emergence of a real Petunia from under the caricature and from under the years-long suppression of personality, is gorgeously wrought and disorienting in the best way. Petunia fragile! And yet I completely believe it, and I'm won over and even somewhat in suspense for her because she feels so flawed -- both in the usual sense, the kind we associate with canon, and in the sense that she has grown so brittle and unstable, to the point that it feels she might break.
I'm persuaded I know who wrote this (although I could be entirely wrong) because of the heartcatching talent for details that anyone else might overlook but that you unerringly select, like Holmes spotting the clues in the room that no one else notices and assembling the truth out of hitherto invisible moments. Your fine-honed, distinctly-worded prose makes them glow against a darker background. This minimalist genius for the perfect detail, along with a lovely, assured obliqueness, submerges half the story in guesswork, suggestion, forcing the reader to fill in the unknown circumstances of Petunia's present with a retrospective sympathy about canon events and a leap into indeterministic hope -- meaning, Petunia's not fated to be the cheese-paring, loveless, dried-up harridan of the Potterverse forever. She can change; she can almost fall apart and put herself back together, and the pieces may be the same but the character is different.
One of the things I most loved about this, apart from the magical storytelling, is this very uncertainty about Petunia's state of mind. This reads almost like the aftermath of a nervous breakdown; she hardly has any idea how to go about the simplest things, and every ordinary transaction seems fraught with terrifying, hopeful possibility. The recurring theme of the workmen is uncannily apt, because Petunia herself is a work in progress. There's also the implicit hint of sexuality, slightly threatening or mortifying for someone so repressed, and the sense of being reduced to commonness. And yet Petunia recognizes new freedom in that commonness, and seems to be getting the hang of ignoring the internalized Dursley voice.
Her hesitance, the difficulty of talking about lost days, lost hopes, lost sister -- the way her pregnancy shuts down the brief blossoming at school, then the way she dreams about recreating her own childhood, imagining two little daughters, sisters, even while we know that she will end up with the opposite -- and the way Harry's arrival on her doorstep delivers the blow of Lily's death, so that he is first and foremost a messenger of grief, as well as giving notice that Petunia has no veto power and no further control over her own destiny -- it rewrites her reasons for behaving so bloodily and makes this new Petunia recognizable in the old. I also love how she ends up in a lower-income city neighborhood, on friendly if nervous terms with a family she would once have scorned, learning to negotiate jackhammers and children in underclothes and impertinent drunks -- and the first stirrings of forbidden desire, the kind of desire she's never had a chance to experience.