Alan allies with the Post Office in the hope his friends can get justice at last, but can he trust the people who have let them down so badly?
| Name | Type | Role | |
|---|---|---|---|
| Gwyneth Hughes | Writer | ||
| Nadhim Zahawi | Guest Star | Nadhim Zahawi | |
| Colin Tierney | Guest Star | Martin Griffiths | |
| Conor Mullen | Guest Star | David Hamilton | |
| Isobel Middleton | Guest Star | Kay Linnell | |
| James Naughtie | Guest Star | James Naughtie | |
| Krupa Pattani | Guest Star | Saman Kaur | |
| Ifan Huw Dafydd | Guest Star | Noel Thomas | |
| John Hollingworth | Guest Star | James Hartley | |
| Amit Shah | Guest Star | Jasgun Singh | |
| Susan Brown | Guest Star | Min Howard | |
| Mark Arends | Guest Star | Richard Roll | |
| Clare Calbraith | Guest Star | Gina Griffiths | |
| James Strong | Director |