Anna Karenina by Leo Tolstoy (1877)

A train pulls into a snowbound Moscow station, a carriage door opens, and Anna steps down into the one glance that will undo her. She has everything the world counts: beauty, wit, an important husband, a place at the centre of Petersburg society. What takes it all from her is not love and not scandal alone but the exact arithmetic of both, a world that winks at a husband's affairs and bolts every drawing-room door against a wife who dares the same. Tolstoy lays a second life alongside hers, Levin out on his estate, scything hay beside his peasants, groping toward a God he cannot name and a happiness he half-distrusts. The wonder of it is the mercy: no one is a villain here, everyone is right inside their own pain. You will dread the final hundred pages and turn them anyway, unable to look away from where the train is going.