Elizabeth Gaskell’s North and South is one of the most approachable 19th-century novels. It has some fine social contrasts (idyllic, clean-air Hampshire, versus grim, polluted Milton), but the comparisons are subtle and the book takes unexpected turns, with northern and southern characters changing each other’s attitudes.

There’s also a nice modern contrast of political viewpoints: John Thornton, the individualistic mill owner, versus Margaret Hale, who discovers community values when she sees the consequences of Thornton’s manufacturing zeal on the local people. And there’s some vivid economic history: the beginnings of trade unions, the conflict between capital and labour, the uncertainties of the cotton trade.

Add in a convincing love story and a believable portrait of life in two very different families, and you have a novel with fine serial potential, which has been realised in these three absorbing episodes, dramatised by playwright Charlotte Keatley. She has been faithful to the text and its complexities but has occasionally added dialogue. For instance, when John Thornton (David Threlfall) has an awkward first meeting with Margaret Hale (Emily Mortimer), Mrs Gaskell hardly dramatises the scene at all. But Keatley has culled new dialogue from various later references to the conversation and created a lively scene of short speeches, which starts off the pattern of mutual attraction and misunderstanding between Margaret and John.

Sunday’s first episode sets up the story well. The southerners’ shock at coming to the land of “smoky chimneys and factory people” is nicely done - particularly the moment when Margaret feels she has to warn her mother about the wallpaper in their rented, three-bedroomed house.

David Threlfall is perfect as the wonderfully succinct and definite Thornton. He creates a powerful presence with relatively few lines, and manages to retain our sympathy despite pronouncements such as “Poverty comes from weakness of character”.

Caroline Mortimer’s Margaret has more to do. She gets both the sweetness and the determination of the character, but her lighter moments seem to have an unfortunate touch of Lizzy Archer about them. Sue Johnstone as Mrs Thornton is a northern rock, and Naomi Radcliffe is a suitably appalling Fanny Thornton.

Direction by Michael Fox is fast and unfussy. Why spoil an excellent story which, in this vivid version, should give English students a helpful nudge towards an accessible novel?