Sirius Black, The Prisoner of Azkaban

Beneath the waning gibbous moon, draped in the tattered raiments of despair, Sirius Black stood and plotted his long nursed revenge, filthy, pale and gaunt.

Azkaban's icy claws had scraped away all joy, cold stone cells bore witness to countless nights devoured by Dementors, each day haunted by stolen lives and betrayal.

"James, Lily... Peter," he rasped, the names tasting of ash, loss and regret.

"Your blood stains the cobbles, your laughter echoes in these accursed halls. But know this, though hope lies entombed within these walls, my heart beats vengeance."

"From this desolate abyss, a storm shall rise, tearing the tapestry of their treachery thread by bloody thread. In every shadow, their guilt shall writhe, in every scream, their reckoning shall toll. For I, Sirius Black, swear upon the pyre of your sacrifice, the tapestry of their lives shall be consumed by flame."

"Vengeance, though shrouded in darkness, will be ours."