To be honest, Essery wasn't sure exactly what it was she had been trying to prove in the debate she'd signed up for - it was either that crises weren't inevitable, or it was that things didn't have to be as they always were. Either way, she knew she was the optimist for tonight, and getting the game going was probably a better way to start.
Also, the idea of sitting down to a game with Severus Snape, even a game of chess, was definitely a little mind bending.
She reached for a pawn, picking him up carefully as she wasn't sure whether or not it was a muggle set and ordering the pieces about seemed a bit daft if it wasn't, but she felt him wriggling in her hand and then rolled her eyes and sat him back. "Sorry," she said to the pawn. "Right then, you. E four." And she smiled up sheepishly at Snape, relaxing into her chair.