Note: This is juvenilia, written when I was a teenager. I'm a bit embarrassed by it, but I'm leaving it up here because a number of people were kind enough to read it and say complimentary things. Feel free to enjoy it, if you will, but don't judge me on it. ;-) - May 2020.
Black Knight, White Queen.
Every player has a weakness. That's the key. If you know what to look for, you can find it, because mostly they don't know themselves. Your have to study your opponent. To understand. She has watched them, and she knows all their weaknesses. She has watched them for a long time.
She knows that Filius always relies too heavily on his bishops, intrigued by the angles, and forgetting the dangers right before his eyes. She knows that Septima places too much emphasis on formation, not understanding that a single pawn can breach every guarded flank. She knows that Albus sacrifices pieces too recklessly, gambles too much, until his king is left defenceless and alone. Every player has a weakness. The key is in finding them.
Minerva was six years old when her eldest sister's boyfriend gave her an enchanted chess set that changed with the tides of her life. When first she touched it, the white queen bore her face, and the black king wore the likeness of Tom Riddle. It was Tom who taught her the rules of the game.
When Minerva was fourteen, the black king commanded legions with the faces of once-friends, and her brother Tristram was his most feared knight. When she was twenty-three, the face of her white king was Fabian Prewett's, and her slender hand beside the chess board bore a silver ring. Fabian always played plain-faced, his blue eyes laughing, and his moves too bold. When Minerva was twenty-four, she taught her first year at Hogwarts School of Witchcraft and Wizardry, and for the first and only time, she taught another the rules of the game. Five years later, the Death Eaters attacked a house in Godric's Hollow, and two brothers were killed. The brothers' names were Gideon and Fabian Prewett. The Death Eaters were Antonin, Bellatrix, Aurelius, Severus and Tristram.
She was almost thirty when she returned to Hogwarts for the last time, defeated and broken. The boy whom she had taught to play was still there, an almost-man now, and changed. She had left him a ragged child, teased and despised, but now he was a thing of sneering and indifferent venom. Still, the flame in his eyes burned vengeful, and the black king's face belonged no longer to Tom Riddle, but to Voldemort.
Of course, in a chess game, no one can change sides.
There was open war then, and for three long years, Severus was gone; dark knight into exile, while the chess set in her office gathered dust. She swore that she would never teach another the game.
When Minerva was thirty-three, he returned. In his grief and anger, he had raged, stormed, wept in a whirlwind of passion, tearing through everything in his path. They had screamed accusations, duelled, wrestled, furious as wildcats in a maelstrom of unleashed and uncontrollable power, until at last in grief and exhaustion, they had fallen into each others' arms and slept, while the enchanted chess set, alone of all her possessions, remained unbroken.
Slowly, painfully slowly, they had re-established the rules of their game. What she had thought known, she learnt anew, testing again his strengths and weaknesses. It took a long, long time, but finally, she had the key. Severus... He played each piece alone, until the bitter end, never able to see his army as a unified whole.
They reached a peace, of sorts. An uneasy truce, long in the making, yet comfortable. They were too different, too the same to allow for anything more. In that time, the pieces changed again, and Harry Potter was both black king and white, the child who must be protected at all costs. Severus' queen was Lily Evans, as she had ever been, and he himself the queen-side knight. It was a long peace; a lull between two wars; and they loved and fought, and laughed at times, Albus' right hand and his left. But Tom Riddle had first been the craftsman, and no gift of his could last forever unchanging.
The war began again, as they had known it must, and Severus played devil's advocate, while Dumbledore and Voldemort faced off across the chequered world. On a clouded, rain-lashed night, they played their last game, guarding the school for Dumbledore's return. For the first time in Minerva's memory, there had been a stalemate. One castle, three pawns, a white queen and a dark knight, protecting kings whose faces were now impossible to discern. Severus stood and drained his glass. As he left, he had kissed her hand.
On the night that Dumbledore died, Minerva wept. On the night that Severus was murdered, she dashed the chess set to riven fragments on the stone floor.
Every player had a weakness. That was the key.