Convicted murderer Henry Stoddard's release from prison coincides with a spate of vandalism, and locals presume he is responsible for the petty crime. But when the former jailbird insists he did not kill PC Machin all those years ago, Walker reopens the case and races to stop Machin's son exacting revenge. Meanwhile, Peggy sees the chance to make some money when her birth certificate suggests she is related to Lord Ashfordly.