the_debt_of_time

"Is everything all right, Sirius?" Harry asked. "You've been acting, well, a bit strange
the past few days."
"How could you tell?" Sirius attempted to joke.
Harry quirked his brow, looking impatient.
"Merlin, you look like Lily when you do that." Sirius chuckled softly, swirling his
drink in the glass. "Would you like to know some things about your family?"
Harry's eyes lit up at the question. "Yeah, of course!"
Sirius stood and walked to a nearby dresser, waving his wand to unlock one of the
cabinets at the bottom. He removed a large book and brought it back to the table. He set
the copy of Nature's Nobility: A Wizarding Genealogy on the table and looked over at Harry.
"I remember this," Harry murmured, reaching for the book. "We found it when we
first came to Grimmauld Place after Bill and Fleur's wedding when we were looking for
the Horcrux. You said that the Potters weren't in here." He looked from the book back to
his Sirius, who had started tugging on the silver chain again.
"I umm... I lied. Potters were in there, but I vanished the page before you could
see it."
"Why would you do that?" Harry asked warily.
"It'll all make sense soon," Sirius promised, opening the book. "It doesn't matter,
though, because you'll find what we need on the Black Family Tree. What do you know
about your grandmother?"
"She was a Black," Harry answered. "Dorea, right?"
"One of the most brilliant witches I've ever known in my entire life," Sirius said
with a smile. "Your grandmother was as Slytherin as they came." He chuckled and watched
as Harry's eyes widened.
"Back then, at least for Dorea, it was a good thing. Slytherins weren't always
synonymous with Death Eaters and prejudice, you know. I was a prat about the House
when I was a kid, but I knew a few that were actually pretty decent. The wizard that
invented the Wolfsbane Potion? He was in Slytherin. Went to school with us, actually. And
there were others," he continued, thinking of Regulus who, apparently, had not turned out
to be all that bad in the end. There was Snape, whom the Wizarding world was calling a
hero these days. And Mia's friend Laurel from the Ministry, who had put a great deal of
effort into trying to help Sirius when Mia had first disappeared.