"La segunda casaca" by Benito Pérez Galdós is a novel published in 1876. It narrates the events leading to the Liberal Triennium in Spain, centered on King Ferdinand VII's opportunistic adoption of the Constitution he had revoked eight years earlier. The story follows various characters including Salvador Monsalud, guerrilla fighter Carlos Navarro, and the cynical Juan Bragas, who switches political allegiances as circumstances demand. The narrative blends melodramatic intrigue with street riots, Inquisition dungeons, and palace scenes, offering a tragicomic chronicle of political opportunism. (This is an automatically generated summary.)