In "Little Dorrit," Amy Dorrit, affectionately known as Little Dorrit, grows up in the constraints of the Marshalsea debtors' prison. Despite the grim surroundings, she maintains her gentle nature and works diligently as a seamstress. Her story intertwines with that of the Clennam family, leading to revelations and transformations that affect all involved.

The Dorrit Family's Confinement

Little Dorrit's early life is marked by her birth in the Marshalsea debtors' prison, where her father is imprisoned for unpaid debts. After her mother's death, Amy and her siblings continue residing in the prison with their father, who is barred from leaving. As she grows up, Amy seeks employment as a seamstress, finding work with Mrs. Clennam, a bedridden widow and businesswoman.

The Return of Arthur Clennam

Arthur Clennam returns to London from the East after his father's passing, intending to claim his inheritance and distance himself from his mother's oppressive influence. Observing Little Dorrit's humble demeanor, Arthur learns of her life in Marshalsea and endeavors to improve her family's dire situation. Despite the complexities of Mr. Dorrit’s financial entanglements, Arthur is determined to help.

Allies in an Unlikely Mission

Arthur gains unexpected allies in his mission, including Pancks, a peculiar rent collector, and John Chivery, the turnkey’s son who harbors unrequited love for Little Dorrit. With assistance from Mr. Rugg, an elderly lawyer, they strive to untangle Mr. Dorrit's debts and secure Little Dorrit's brother's release from trouble. Arthur also supports Amy by finding more sewing work and offering financial aid to the family.

Sudden Fortune and Social Ascension

Pancks uncovers that Mr. Dorrit is heir to a substantial fortune, enabling his release from the prison after more than twenty years. The newfound wealth transforms the Dorrits, who attempt to erase their past by embracing a newfound social status. Although Mr. Dorrit and his elder children distance themselves from Arthur, perceiving his previous assistance as patronizing, Little Dorrit remains unchanged by their fortune.

Life Among Expatriates

The Dorrit family relocates to the Continent to reinvent themselves, mingling with British expatriates who are unaware of their history. Fanny Dorrit, Amy's older sister, attracts the attention of Mr. Sparkle, stepson to Mr. Merdle, a celebrated banker. Although not genuinely in love, Fanny is tempted by the allure of wealth and status, leading to a marriage sanctioned by the Merdles, who overlook her humble origins.

Arthur's Growing Concerns

Meanwhile, Arthur stays in London, consumed by the enigmatic visitors at his mother's house and managing his own faltering business. Among these visitors is Monsieur Blandois, a nefarious figure whom Arthur suspects of foul play. Flintwinch, his mother's unscrupulous clerk, also raises Arthur's suspicions, adding to the mounting tension in his life.

Descent into Debt

Arthur's financial woes worsen as he invests heavily in Mr. Merdle's ventures, hoping for quick profits. When the purportedly infallible banker falls into ruin, Arthur's fortunes vanish, leaving him bankrupt and imprisoned in Marshalsea, where he occupies Mr. Dorrit's old quarters. Though Mr. Rugg and Pancks strive to expedite his release, Arthur's spirit is broken until Little Dorrit arrives to comfort him.

Truth and Redemption

Pancks tracks down Monsieur Blandois, whose actions precipitate a crisis for Mrs. Clennam. Faced with the threat of blackmail, she reveals a long-held family secret: Arthur is not her biological son, and she has withheld his rightful inheritance, as well as money owed to Little Dorrit. With the truth unveiled, Arthur gains his freedom, and he and Little Dorrit, now united by love and shared trials, marry.