《波尔达克》第4季的剧情主要延续了之前的故事线，深入描绘了主人公Ross Poldark及其周围人物的生活和情感变化。在本季中，Ross Poldark在经历了一系列挑战和变故后，逐渐适应了新的生活状态。他继续致力于家族锡矿的开发，并在事业上取得了一定的成就。同时，他与妻子Demelza Carne的感情也愈发深厚，两人共同面对生活中的种种困难，相互扶持，共同成长。此外，本季还着重展现了Elizabeth Chynoweth和George Warleggan的生活变化。Elizabeth在成为寡妇后，改嫁给了Ross的劲敌George Warleggan，她的生活也因此发生了巨大的转变。而George Warleggan与Ross之间的对立和竞争也愈发激烈，为剧情增添了更多的紧张感和悬念。Ross (Turner) must defend Cornwall from an empowered George Warleggan (Jack Farthing), and risks everything he holds dear as he embarks on a political journey which takes him to the nation's capital. Demelza (Tomlinson) finds her loyalties torn, Elizabeth (Heida Reed) tries to strengthen her marriage, Morwenna (Ellise Chappell) continues to be oppressed by husband Reverend Ossi...