Once upon a time.
What a captivating phrase it was.
An aging elder could use it to reminisce about the passionate days of youth, a traveler far from home could use it to yearn for their homeland, and even a bewildered young person could use it to fend off an unknown future.
But the past had always been a two-sided mirror. If it reflected happiness, it reflected pain as well.
An aging elder would see their own decline in their youth, a traveler far from home would see their loneliness in their homeland, and those bewildered young people would see their uncertainty in their happy memories.
For Sirius, this was especially true.
The past reflected his happiness, but also his pain.
James, James...
Whenever Sirius remembered the happiness he had shared with James, what followed was his best friend's death, a friend's betrayal, and twelve years of bitter torment.
Twelve years was a very, very long time, enough to change a person and erase certain things from their heart.
There was only one exception.
Something that, throughout those twelve years, had been honed within the heart, growing sharper and sharper.
So that whenever the past was brought up, it would slice the heart open again, leaving it dripping with blood.
The lone candle flame suddenly flickered, briefly illuminating Sirius's gaunt face before withdrawing its light.
"Back then, after turning down your offer to be his Secret Keeper, James originally wanted me to do it," Sirius said.
"Everyone thought so," Dumbledore nodded. "Even I was no exception."
At the time, Dumbledore was already the Order of the Phoenix's Secret Keeper and a target of the Death Eaters himself. The danger he faced was no less than that facing the Potters, perhaps even greater. On top of that, the person James trusted