Set in Victorian London, the narrative centers on Arthur Clennam, who returns home after years abroad in China following his wealthy father’s death. Haunted by a dying wish and a mysterious pocket watch inscribed with the initials "D.N.," Arthur suspects his austere, controlling mother, Mrs. Clennam, holds a dark secret involving the ruined Dorrit family. Motivated by a desire to make amends for past family wrongs, Arthur takes a kindly, selfless seamstress, Amy "Little" Dorrit, under his wing.Amy works tirelessly to support her family while living in the Marshalsea debtors' prison, where her proud, eccentric father, William Dorrit, has languished for over two decades. Known as the "Father of the Marshalsea," William believes his aristocratic birth justifies his entitlement, completely oblivious to the degrading reality of his confinement. Arthur uses his influence to help secure William’s release after a staggering inheritance reveals the Dorrits are actually the rightful heirs to a massive fortune.Instantly wealthy, the family flees England for the grand capitals of Europe, desperately trying to buy their way into high society and bury their sordid past. However, sudden riches corrupt them; William becomes obsessed with erasing any memory of the prison, forcing Amy to hide her humble origins. Amidst this upheaval, Arthur faces financial ruin himself. He invests disastrously in the fraudulent schemes of the charismatic speculator Mr. Merdle, whose sudden suicide triggers a massive economic crash that ruins countless investors, including Arthur.Consequently, Arthur finds himself imprisoned for debt in the very same Marshalsea cell where the Dorrit saga began. Meanwhile, abroad, William suffers a public
psychological break, tormented by his repressed past, and dies shortly after. Amy, entirely unsuited by her gentle nature to the artificial aristocracy, rushes back to England upon hearing of Arthur’s
imprisonment.Nursing Arthur through a severe, near-fatal fever, Amy’s steadfast devotion finally pierces his emotional armor. In a parallel subplot, the malicious solicitor Mr. Flintwinch and his blackmailing brother uncover Mrs. Clennam’s past secrets—revealing that Arthur is not actually her biological son, but the child of the woman her husband wronged, and that Amy is the true key to the Dorrit inheritance. Ultimately, the Clennam household collapses in literal and financial ruin. Cleared of his debts and unburdened by his mother’s bitter legacy, Arthur realizes his deep love for Amy. They leave the shadows of the Marshalsea behind, marrying quietly and embracing a humble, hopeful future together.