Part one of an ambitious six-hour adaptation of Charles Dickens' novel starts with the return of Arthur Clennam (Derek Jacobi) to London after for several years in China. A mysterious watch left to him by his dying father estranges him from his cold-hearted mother, but not before Arthur meets her enigmatic young seamstress, Amy Dorrit. Suspecting that his mother is the reason Amy is living in Marshalsea debtors' prison with her father (Alec Guinness), brother and sister, Arthur offers to help.