An exhausted young woman staggers into a provincial workhouse in the middle of the night, gives birth and dies. In the absence of any identification her newborn son is arbitrarily named 'Oliver Twist' by Mr. Bumble, the negligent parish beadle ('a fat man, and a choleric one... [with] a great idea of his oratorical powers and his importance'). Bumble promptly places him in the care of the ill-tempered Mrs. Corney and the drunken Mrs. Mann in the workhouse orphanage, where he grows up 'without the inconvenience of too much food or too much clothing'.
When he reaches the age of nine he is transferred to the workhouse proper and set to work. Drawing the short straw in a lottery amongst his starving fellow inmates, it falls to Oliver to ask for more gruel, the staple diet of the workhouse. As a result he is put to a trade: after narrowly escaping employment as a chimney sweep's boy, he is placed under the care of Mr. and Mrs. Sowerberry. They run an undertaking business with the assistance of the snivelling bully Noah Claypole ('a large-headed and small-eyed youth, of lumbering make and heavy countenance') and their vindictive maid, Charlotte. When Noah insults his mother, Oliver attacks him. Bumble's analysis is as follows: '"It's not madness, ma'am", [he replied] after a few moments of deep meditation. "It's meat."' As a result of the cruel punishment that follows, Oliver flees.
Arriving in London, he is immediately befriended by an urbane, cheerful boy named Jack Dawkins, otherwise known as the Artful Dodger- 'one of the queerest-looking boys that Oliver had ever seen'. The Dodger takes him to the squalid lair of Fagin, 'a very old shrivelled Jew whose villainous-looking and repulsive face was obscured by a quantity of matted red hair'. Fagin decides to apprentice the hopelessly naïve Oliver to him as a pickpocket.
Having learned the necessary tricks, Oliver is sent out with the Dodger and his cohort Charley Bates to ply his new trade. Horrified by the sight of their pick pocketing a gentleman at a bookstall, Oliver flees but is pursued as the culprit and brought before a magistrate. However, the gentleman, Mr. Brownlow ('a very respectable-looking personage, with a powdered head and gold spectacles'), witnesses the flight of the Dodger and Charley. He is thus able to exonerate Oliver, who arouses sufficient pity in him to be taken to his house, where the kindly housekeeper, Mrs. Bedwin, nurses him through a fever. He is treated with a consideration and sympathy hitherto unknown to him, and is happy for the first time. In Bedwin's sitting room hangs a portrait of a woman of which Oliver is 'a living copy. The eyes, the head, the mouth; every feature was the same'. The juxtaposition causes Brownlow to start violently, but nothing is made of it at the time.
Meanwhile, Fagin is desperate for Oliver's safe return, as he is a potential informer. To this end he recruits the vicious robber Bill Sikes ('a stoutly-built fellow of about five-and- thirty... [with] a beard of three days' growth and two scowling eyes; one of which displayed various parti-coloured symptoms of having been recently damaged by a blow') and his pathetic mistress, Nancy. They are swiftly successful in their search for him, and he is expertly kidnapped whilst on an errand for Brownlow. Back in Fagin's clutches, Oliver is sent with Sikes to assist at a break-in in the countryside. Detected whilst effecting his entry, Oliver is shot and Sikes escapes. The householder, Mrs. Maylie, accepts Oliver's fantastic story and takes him in. He is treated with exceptional kindness by her and her beautiful niece, Rose, who is 'in the lovely bloom and spring-time of womanhood... she was not past seventeen... so mild and gentle; so pure and beautiful'.
This idyll is threatened when Rose develops a sudden illness. Mrs. Maylie's strapping son Harry arrives and implores Rose to marry him on her recovery. She refuses him because she is ignorant of her antecedents, having been adopted from a workhouse orphanage (or 'baby-farm'). With the help of the Maylies' friend Dr. Losberne, Brownlow is traced. Whilst staying with the Maylies Oliver catches terrifying glimpses of a sinister man spying on him; he turns out to be Monks, an agent of Fagin. Fagin himself is observed spying on Oliver but disappears without trace, thereby acquiring a diabolic aspect- 'there were not even the traces of recent footsteps, to be seen'. Back at the den, Nancy overhears Fagin and Monks plotting to deliver Oliver once more into Fagin's hands. Overcome with pity, she reveals the details to Rose in a clandestine, emotionally-charged interview ('"Lady! Dear, sweet, angel lady... Do not mind shrinking