This is a very hard one for me to judge, and I don't feel it would be fair to bring down its stars average, since I personally am not into bitter-professor-Snape+student-Harry. (I've more-fully enjoyed some Snape fics where his life is changed/ rerouted younger, and/or he's matched with someone of his own generation.) I really only read this to see if its obviously-skilled author could win me over, and it didn't quite do that.
It doesn't paint Snape through implausibly rose-colored lenses as so many do, and it has some pretty questionable dynamics for a while (though I can't discuss the progression of their interactions without major spoilers), but I was never bored, and I was ultimately glad for the happy/hopeful ending.
There are some very clever ideas (one minor bit related to the Potterverse time-travel paradigm I did more or less guess), and some decisions that really to me are not so wise (half of Harry's motivations he himself doesn't understand), but both leads, and their conflicts, are thoughtfully drawn.
It's mainly told from Harry's PoV, but we do eventually get to see what's going on in Snape's mind, why he reacted as he did.
TAGS FROM AO3: Fandoms: Harry Potter - J. K. Rowling Rating: Explicit No Archive Warnings Apply Genre: M/M Complete Work Relationship(s): Harry Potter/Severus Snape Characters: Harry Potter, Severus Snape, Ron Weasley, Hermione Granger Additional tags: Hurt/Comfort, Time Travel, Angst with a Happy Ending, Post-Book Seven, Canon Compliant, Fix-It