Keith Allen plays William Palmer in this true story of a Victorian-era English surgeon who uses poison to settle scores and ward off debt. William lacks a sense of regret, even after killing his wife, brother and three of his own children.
| Actor | Role |
|---|---|
 Keith AllenDr. William Palmer | Dr. William Palmer |
 Jayne AshbourneAnnie Palmer | Annie Palmer |
 Linda BassettMary Thornton | Mary Thornton |
 Judy CornwellMrs. Palmer | Mrs. Palmer |
 Richard CoyleJohn Parsons Cook | John Parsons Cook |
 Ben MilesThomas Palmer | Thomas Palmer |
 Dominic BorrelliSamuel Cheshire | Samuel Cheshire |
 Ron DonachieLeonard Bladon | Leonard Bladon |
| CChristian BurgessGeorge Palmer | George Palmer |
| JJohn BleasdaleHenry Bladon | Henry Bladon |