Young orphan Esther Summerson (Anna Maxwell Martin) is brought to the High Court of Chancery by lawyer Mr Kenge (Alistair McGowan). There she's thrown together with two wards of the court, Richard Carstone (Patrick Kennedy) and Ada Clare (Carey Mulligan).
Both are caught up in the infamous suit of Jarndyce and Jarndyce, which brings nothing but ruin and despair to all it touches.
At the Chancery courts, the three meet other beleaguered participants in the case, including the eccentric Miss Flite (Pauline Collins), who lodges nearby with the peculiar, and drunk, rag and bottle merchant, Krook (Johnny Vegas).
They have another lodger, Nemo (John Lynch), a very mysterious figure. He's a law-writer by trade, but a self-destructive opium addict by nature. When Esther bumps into him, she feels a strange shiver of recognition.
Esther, Richard and Ada spend their last night in London with the Jellyby family, before setting off to Bleak House to live with their new guardian John Jarndyce (Denis Lawson).
They are astonished to find the Jellyby household running to ruin as a result of Mrs Jellyby (Liza Tarbuck) spending more time dealing with far-flung matters of philanthropy than the problems on her own doorstep. Esther sympathises with her daughter, Caddy (Natalie Press), who is at her wits' end.
Esther, Ada and Richard receive a warm welcome at Bleak House from Mr Jarndyce. There they are introduced to his friend, Harold Skimpole (Nathaniel Parker), a man who shirks responsibility for his actions, as well as the public-spirited Mrs Pardiggle (Roberta Taylor). She escorts Esther, Ada and Richard on a charitable excursion to the slum dwellings of some poverty-stricken brick makers. There they witness the death of Jenny's (Charlie Brooks) baby.
Later, Guppy (Burn Gorman), a Lawyer's clerk, declares his feelings for Esther and proposes marriage. But Esther turns him down, saying she could never marry him.
Meanwhile, the elegant life of the beautiful Lady Dedlock (Gillian Anderson) is turned upside down when her husband's lawyer, Tulkinghorn (Charles Dance), gets wind of a secret from her past. She recognises the handwriting on a legal document, and Tulkinghorn determines to find out the name of the writer.
Tulkinghorn's investigation leads him into the dark underbelly of London, where he discovers that the writing belongs to Nemo. But when Tulkinghorn finally tracks Nemo down, he discovers that the law-writer is dead...
Tulkinghorn (Charles Dance) and Krook (Johnny Vegas) call out the doctor, Allan Woodcourt (Richard Harrington). He suspects that Nemo's (John Lynch) death was caused by an accidental overdose of opium.
The Coroner (Peter Guinness) confirms as much. Nemo is given a pauper's funeral. At the gloomy burial ground Tulkinghorn interrogates a young crossing-sweeper, named only Jo (Harry Eden), whom Nemo had befriended. He's convinced Jo knows something.
Meanwhile, Ada (Carey Mulligan) and Richard (Patrick Kennedy) are beginning to fall in love. Jarndyce instructs Richard that it's time to choose an occupation. Very quickly, he decides upon a career in medicine.
As a result, arrangements are made for Richard to study with Mr Bayham Badger (Richard Griffiths) in Chelsea. The four have dinner with him and the irrepressible Mrs Badger (Joanna David) who continually talks about her former husbands. There they encounter Allan Woodcourt. He and Esther are attracted to one another.
At Chesney Wold, Lady Dedlock (Gillian Anderson) has taken a shine to the young maid Rosa (Emma Williams) – to the absolute horror of her existing French maid, Hortense (Lilo Baur).
However, Lady Dedlock has more serious troubles when Tulkinghorn gleefully informs her that Nemo is dead. Later, as Lady Dedlock sits alone in the darkness, she sheds a tear.
Meanwhile, Krook (Johnny Vegas) is gloating over a bundle of letters he filched from Nemo's trunk under Tulkinghorn's nose. Although he can't read, he thinks they smell like love letters.
Ada (Carey Mulligan) confides in Esther (Anna Maxwell Martin) that she and Richard (Patrick Kennedy) are in love. They wish to get engaged, but their guardian Jarndyce (Denis Lawson) disapproves and tells them it's far too soon to take this step. Reluctantly the pair agree to wait.
Meanwhile, Richard's struggling with his medical studies, and decides to quit in favour of the law. But with his increasing obsession in matters at Chancery, will he come to regret the decision? In court with Ada, he meets Mr Gridley (Tony Haygarth) – an irascible and frustrated suitor who has wasted his life in pursuit of reward. Gridley flies off the handle at Tulkinghorn, who, enraged, orders a warrant for his arrest.
Caddy Jellyby (Natalie Press) tells Esther she's entered into a secret engagement with Prince Turveydrop (Bryan Dick), the son of a dancing master. His father, Old Mr Turveydrop (Matthew Kelly), is a lazy, self-centred old man who preens around, showing off his deportment, whilst his son does all the work.
Esther is also falling in love - she and Allan Woodcourt (Richard Harrington) have become close. But she's deeply disappointed to hear the news that he's taken a job as a ship's surgeon on a long voyage. A little hope remains, however, when she receives some flowers from him as a keepsake.
Skimpole (Nathaniel Parker) joyfully announces that his old adversary, Mr Neckett the bailiff, has died. But when Jarndyce and Esther hear that he had a young family, they decide to visit his lodgings. There, they find that his daughter, Charley (Katie Angelou), is working as a washerwoman to provide for her siblings. Jarndyce resolves that they should take action.
Elsewhere, Lady Dedlock (Gillian Anderson) instructs Tulkinghorn (Charles Dance) to cease his enquiries about Nemo (John Lynch). Nonetheless, she decides to conduct her own secret investigation tracking Jo (Harry Eden), the crossing sweeper, down at night and paying him to guide her around Nemo's old haunts. Finally, she visits his burial ground, where she's overcome with grief.
Jarndyce (Denis Lawson) takes Esther (Anna Maxwell Martin) and Ada (Carey Mulligan) to visit his friend, Mr Boythorn (Warren Clarke), in the Leicestershire countryside.
In the local church, Esther has a strange encounter with Boythorn's neighbour Lady Dedlock (Gillian Anderson) in which both feel a mysterious pull of recognition.
Later, on a country walk, Jarndyce, Esther and Ada are caught in a storm and take shelter at the same place as Lady Dedlock. She asks Jarndyce for confirmation that Esther is indeed an orphan. Then, after listening to another unruly outburst, Lady Dedlock sacks her fiery maid, Hortense (Lilo Baur).
Meanwhile, Jarndyce is jealous to overhear Esther tell Ada about her affection for Woodcourt (Richard Harrington). He's starting to have feelings for Esther himself...
Back in London, Richard (Patrick Kennedy) is now working at Kenge and Carboys, and showing an unhealthy interest in the Jarndyce and Jarndyce suit.
Guppy (Burn Gorman) pays a visit to Snagsby's (Sean McGinley) law-writing shop, where he meets Mrs Chadband (Catherine Tate). She happened to work for Miss Barbary, Esther's former guardian, in the past, and informs Guppy that Esther's real surname is Hawdon.
Guppy decides to investigate further by chasing the matter up with Krook (Johnny Vegas). But Krook is so wily – and so drunk – that he doesn't get very far.
A policeman has also called at Snagsby's with Jo (Harry Eden), the crossing sweeper, in tow. Jo has a substantial amount of money in his possession, and the policeman doesn't believe his story about the lady who gave it to him.
Snagsby takes Jo's story to Tulkinghorn, and is introduced to Inspector Bucket (Alun Armstrong). After finding Jo, they bring him to Tulkinghorn's (Charles Dance) office, where he's startled to see what appears to be the same lady who gave him the money.
Richard (Patrick Kennedy) puts further strain on his relationship with Jarndyce (Denis Lawson) by announcing his intention to quit the law and join the army. Jarndyce warns him that this must be his final choice of career, and that he needs to take his employment seriously, since no good will ever come of his Chancery hopes.
Charley Neckett (Katie Angelou) turns up as a not wholly welcome gift for Esther. Jarndyce has employed her as Esther's (Anna Maxwell Martin) maid without consulting her first.
Elsewhere, Caddy (Natalie Press) and Prince (Bryan Dick) announce their engagement to Old Mr Turveydrop (Matthew Kelly). He is most displeased, until they pledge to work together to make his life more agreeable.
Gridley's (Tony Haygarth) on the run from the law, following Tulkinghorn's arrest warrant. He asks his old friend, Miss Flite (Pauline Collins), if she can take him in. But she points him in the direction of Sergeant George (Hugo Speer), a noble ex-soldier who now owns a gym. Among his fencing pupils is Richard, who's learning the arts of war in preparation for joining his regiment.
Unfortunately for George, he has become embroiled in Tulkinghorn's (Charles Dance) investigation. Clamb (Tom Georgeson) has managed to identify Nemo (John Lynch) as a Captain Hawdon, in debt to the moneylender Smallweed (Phil Davis). George was a close friend of Hawdon's during their army days, and he now also owes Smallweed money.
Tulkinghorn desperately wants to get hold of a sample of Hawdon's hand-writing for comparison. He sends Smallweed to blackmail George into providing a letter from Hawdon. But George isn't interested in helping.
Meanwhile, Inspector Bucket (Alun Armstrong) follows Miss Flite to the gym where a dying Gridley is discovered. Before an arrest can be made, Gridley passes away.
Guppy calls on a drunken Krook, who offers him a glimpse of the love letters he found. Lady Dedlock also receives a visit from the clerk, who reveals that he knows Esther's real name is Hawdon — but the aristocrat has other worries after hearing her beloved maid Rosa is set to marry. Tulkinghorn meets George to discuss his demands, leaving the ex-Army man worried about his future, and Jo becomes seriously ill.
George has to make an impossible decision when Tulkinghorn and Smallweed turn up the heat on his debts. Guppy's quest for information takes him back to Krook's shop, with explosive results. Jarndyce is beside himself when tragedy strikes Bleak House.
Tulkinghorn is now close to piecing together Lady Dedlock's secret. Esther struggles to come to terms with the terrible blow she has been dealt. Jarndyce agonises over whether to keep his own feelings for Esther concealed. And then Lady Dedlock tells Esther something that will change her life for ever.
Esther is shattered by Lady Dedlock's revelation. Richard's obsession with the Jarndyce case has grown to worrying proportions. Guppy puts himself at risk when he gets in the way of Tulkinghorn's enquiries. And Tulkinghorn at last has cast iron proof of Lady Dedlock's guilt, and issues her with a terrible ultimatum...
Believing Lady Dedlock to be in his power, Tulkinghorn continues to add to his list of enemies, incurring the wrath of both Hortense and Sergeant George.
Meanwhile, Esther plans a visit to London, with Ada, but what's her ulterior motive? And how is Richard going to repay Vholes and Skimpole the huge debts he's built up?
Richard is in dire straits but Ada and Esther may be too late to help him. An unexpected meeting with Woodcourt raises uncomfortable questions for Esther. Jo the crossing sweeper is critically ill, and despite Woodcourt's best attempts it is a matter of life and death. And Tulkinghorn discovers Lady Dedlock's defiance with disastrous consequences.
Clamb discovers Tulkinghorn's body and is quick to tell Bucket that George was spotted at the scene of the crime. A shocked Sir Leicester offers a reward for the arrest of the murderer, while his troubled wife shows little reaction to the news. As Woodcourt treats Caddy and her new baby, Ada speculates on his feelings for Esther - who is then forced to reveal her engagement to Jarndyce.
Woodcourt informs Esther of Richard's deteriorating health. Mrs Rouncewell is overjoyed when she discovers George is no longer a suspect in the murder investigation - and informs her son of an employment opportunity at Chesney Wold. The pressure on Lady Dedlock proves too much when Smallweed reveals he has evidence of her secret past - forcing the desperate aristocrat to make a terrible decision.
Months have passed since the dramas surrounding Tulkinghorn's death, in the final instalment of the Charles Dickens adaptation. Ada worries that a desperately ill Richard will not live to see the child they are expecting. Esther is forced to turn down the heartfelt advances of Woodcourt, and Smallweed makes a discovery that leads to the sudden conclusion of the long-running Jarndyce case - but the result shocks everyone concerned.