| The story of Victorian serial killer Mary Ann Cotton, a poisoner whose methods leave no visible scars, allowing her tally of victims to mount, unsuspected by a Victorian society unable to conceive of a woman capable of such terrible crimes. Traveling around the North East, she insinuates herself into unsuspecting families, marrying and creating new families of her own - before killing them, taking their money and moving on. |
| Name | Character | Episodes |
|---|---|---|
| Joe Armstrong | Joe Nattras | 2 |
| Joanne Froggatt | Mary Ann Cotton | 2 |
| Emma Fielding | Helen Robinson | 2 |
| Alun Armstrong | George Stot | 2 |
| Jonas Armstrong | Joe | 2 |
| Bill Fellows | Mr. Brownlee | 2 |
| Thomas Howes | George Ward | 2 |
| Michael Culkin | Sunderland vicar | 2 |
| John Bowler | Mr. Johnson | 2 |
| Seamus O'Neill | William Calcraft | 2 |
| Sam Hoare | James Robinson | 2 |
| John Hollingworth | Dr. John Maling | 2 |
| Shaun Prendergast | Sgt Hutchinson | 2 |
| Paul Brennen | Mr. Riley | 2 |
| Laura Morgan | Maggie Cotton | 2 |
| Mark Underwood | Fred Cotton | 2 |