Tulkinghorn believes Lady Dedlock is in his power, but she continues to defy him. George's anger knows no bounds when Tulkinghorn breaks his promise and leaves him in financial ruin. And a marriage proposal surprises Esther - but is it from the right man?

Richard is in dire straits but Ada and Esther may be too late to help him. An unexpected meeting with Woodcourt raises uncomfortable questions for Esther. Jo the crossing sweeper is critically ill, and despite Woodcourt's best attempts it is a matter of life and death. Tulkinghorn discovers Lady Dedlock's defiance with disastrous consequences.

Esther's feelings for Woodcourt grow stronger despite her best intentions. Inspector Bucket begins his murder investigation with no shortage of suspects. An early arrest appears to wrap the case up quickly, but a spate of poison pen letters suggests that all is not as it seems.