| Name | Character | Episodes |
|---|---|---|
| Claudia Jessie | Lucy | 9 |
| Susan Wokoma | Frankie | 9 |
| Rutger Hauer | Tillman | 7 |
| Sanjeev Bhaskar | Mr. Pradeep | 6 |
| Daniel Mays | Anthony De La Mer | 6 |
| Chris Wilson | Porter | 6 |
| Tanya Franks | Jane Bison | 6 |
| James Atherton | Dr. McKenzie | 4 |
| Sinéad Keenan | Dr. Bartholomew | 3 |
| Jo Joyner | Dr. Kelly | 3 |
| Siobhán McSweeney | Alice | 3 |
| Kelsey Grammer | Mendel Dolem | 1 |
| Marc Warren | Graham Post | 1 |
| Sophie McShera | Pippa | 1 |
| Bryony Hannah | Penny | 1 |
| Mathew Horne | Mark | 1 |
| David Yip | Dalai Lama | 1 |
| Ekow Quartey | Billy Tarsal | 1 |
| Jamie Foreman | Alan | 1 |
| Samantha Spiro | Rebecca | 1 |
| Neil Stuke | Hutch | 1 |
| Jon Glover | Howard | 1 |
| Souad Faress | Freda | 1 |
| Sanjeev Kohli | Muzz | 1 |
| Sally Lindsay | Linda Porter | 1 |
| Scott Chambers | Cheese | 1 |
| Laura Checkley | WPC Newman | 1 |
| Paul Longley | David | 1 |
| Toby Williams | Terry Grimm | 1 |
| Toby Williams | Terry | 1 |
| Rich Keeble | PC Mortimer | 1 |