Memorable literary moments often depend on contrasts. In one such scene in Our Mutual Friend, the newly rich, but illiterate, Boffin tells the one-legged street vendor Silas Wegg, who can just about read: “Here I am, a man without a wooden leg, and yet all print is shut to me.” “Education neglected,” growls Wegg.

To rescue Charles Dickens’s last completed novel, first published in serial form in 1864-5, from neglect, the BBC has adapted and serialised it in four 90 minute episodes. Against a background of stark social contrasts, it tells the story of two love affairs.

In one, John Harmon is told that his inheritance depends on his marrying Bella Wilfer. Since he’s never met her, he assumes a false identity and, penniless, becomes a tenant in her house. She, however, is determined to marry out of poverty and rejects his advances.

In the other story, two men - the charismatic Eugene Wrayburn and the passionate Bradley Headstone - both fall in love with Lizzie Hexham, a working-class girl, who is torn between her love for Eugene and her fear of Bradley.

As so often in Dickens, these stories are shown in a way that explores the class tensions of Victorian life. Here, we travel among the poverty-stricken scavengers on the banks of the Thames as well as in the highest echelons of polite society, the camera lingering on smoky hovels as well as on lavish feasts.

Dickens’s satirical touch is always present. At one high-society occasion, a lap-dog is shown eating off a silver platter. Then the camera cuts to the “dustheaps”, where toiling workers recycle waste to produce the profits that fuel the novel’s plot. “Money and goods are the best references” is a key line.

Adapted by Sandy Welch and directed by Julian Farino, Our Mutual Friend will be useful to students because it makes a book which many find difficult a lot clearer. Most of the scenes are highly atmospheric, with sharp contrasts between brightly-lit ballrooms and dingy tenements.

With a cast whose cameo performances stick in the mind more than the star actors, familiar figures such as Margaret Tyzack (Lady Tippins), Timothy Spall (Mr Venus), Kenneth Cranham (Silas Wegg) and Peter Vaughan (Boffin) convey Dickens’s love of caricature.

While Steven Mackintosh’s Harmon and Anna Friel’s Bella Wilfer are good at suggesting the novel’s themes of disguise and concealment, it’s left to Paul McGann’s Wrayburn, David Morrissey’s Headstone and Keeley Hawes’s Lizzie Hexam to stir the passions.

While this adaptation occasionally has a Dickensian theatricality, it lacks an authorial voice. Since some of the most memorable passages in the book are the epic descriptions of London and the Thames, what’s missing here is a voiceover which could conjure up these images.

Instead, the film is rather restrained. In place of Dickens’s vision of an infernal city, a hell on earth, what we see is a rather tidy metropolis, lacking the violence and disorder that are never far below the novel’s narrative.On the other hand, restraint does have its advantages. Many of the locations - such as the gloomy tunnels under the police station - are highly memorable, and neat images - a cigar stubbed out in a wedding cake - often prove eloquent enough.

This adaptation flows with a slow and unhurried pace. Although sympathetic to the original book, you sometimes wish that the unbuttoned vivacity and fantastical imagination of Dickens could have been better captured.

Teachers will find this film a useful aid to discussing the book. To help them, there’s a half-hour documentary which deals with some of its key themes, as well as emphasising Dickens’s lifelong interest in education. It argues that in the 1860s his novel helped raised middle-class awareness of the condition of the London poor, especially children.

The documentary on the series will be shown on Monday, March 30, from 7.30-8.00pm on BBC2. There is also a tie-in edition: ‘Charles Dickens, Our Mutual Friend’, Penguin pound;3.99. A booklet, ‘Our Mutual Friend: A Viewer’s Guide’ is available from BBC Education, PO Box 7, London W12 8UD, pound;4.99