Amy Dorrit's (Claire Foy) gentle spirit has never been dampened by the confining walls of the Marshalsea Prison she's lived in her whole life. Despite the dark shadow of debtor's prison, Amy lovingly cares for her father William Dorrit (Tom Courtenay), the longest serving inmate. A possibly redemptive light unexpectedly shines in the form of Arthur Clennam (Matthew Macfadyen), who has been left with the intriguing threads of a mystery after his father's death -- threads that will intertwine his family and fate with the Dorrits. Clennam's exhaustive search for answers involves murder, fortunes gained and lost, the upper echelons and lowest dregs of society, and most surprising of all, a tender romance.