The plot, in a nutshell, is that Margaret Hale and her family move from southern to northern England and experience culture shock. The North is dark, dirty, industrial, ruled by factory owners who seem more interested in profit than their workers. Workers are growing agitated. Margaret's father is tutoring one of the mill owners, Mr. Thornton. At first Margaret and Mr. Thornton are at odds with each other, but of course that changes. And it being a Victorian novel written by a woman, events unfold in a way that lands the heroine with all the money and power, able to act as an independent agent, while the hero has lost everything. Ah, romance. I love the Victorian era. The Industrial Revolution changes the landscape entirely - from the actual physical topography to the social, economic, and class structure. It's the boom before the bust, though of course it was always a bust for the children working in factories and those dying from breathing in cotton dust.
Besides finding the leads very pretty to look at (and oh my are they), I think the cinematography is general is beautiful, and the soundtrack is gorgeous. I love the way the main melody changes over the course of the series. Also, they did something to the heroine's makeup that is completely un-Victorian, but it makes her glow.
There's a scene at the end of the first episode that made a particular impression on me. Margaret is expressing her despair at living in this harsh Northern mill town, "I believe I've seen hell. It's white. It's snow white." Then we are inside a Victorian cotton mill, cotton fluff floating through the air like snow. And the music, oh it's just perfect.
Isn't that beautiful?