| Name | Character | Episodes |
|---|---|---|
| Jesse Spencer | Fritz Robinson | 2 |
| Liam Cunningham | David Robinson | 2 |
| Roger Allam | Thomas Blunt | 2 |
| Francis Magee | Pickles | 2 |
| Rupert Holliday-Evans | Roberts | 2 |
| Neil Newbon | Ernst Robinson | 2 |
| Bonnie Wright | Young Sarah Robinson | 1 |
| David Yelland | Captain Montrose | 1 |
| Andrew-Lee Potts | Jacob Robinson | 1 |
| Emma Pierson | Sarah Robinson | 1 |
| Jenna Harrison | Emily Montrose | 1 |
| Philip Voss | Judge | 1 |
| George Costigan | Quirk | 1 |