With Nikki missing, Harry works against the clock to find out who is responsible for the murders and finds himself in a cover-up.
| Name | Type | Role | |
|---|---|---|---|
| Christian Spurrier | Writer | ||
| Pete Ashmore | Guest Star | DI Merson | |
| Nicholas Jones | Guest Star | Dr Harvey Wilson | |
| Andrew Havill | Guest Star | Alan Garnett | |
| Ella Jones | Guest Star | Justine Finch | |
| Damien Goodwin | Guest Star | Roger Hewitt | |
| Kate Lynn-Evans | Guest Star | Sylvia Clune | |
| Sam Spruell | Guest Star | Robbie Sharpe | |
| Emma Shaw | Guest Star | Amelia Brown | |
| Jonny Phillips | Guest Star | Simon Traynor | |
| Caroline Lord | Guest Star | Receptionist | |
| Dido Miles | Guest Star | Lydia Carpenter | |
| Joseph Mawle | Guest Star | Adrian Burney | |
| Jemima Rooper | Guest Star | Claire Ashen | |
| Paul Panting | Guest Star | DCI Bob Mumford | |
| David de Keyser | Guest Star | Sir Peter Greenfield | |
| Antonia Campbell-Hughes | Guest Star | Fenella Lee | |
| Mark Weller | Guest Star | PC Fraser Caine | |
| Carrie Davies | Guest Star | Madeline Fischer | |
| Nicholas Le Prevost | Guest Star | Prof Lionel Clune | |
| Jonathan Guy Lewis | Guest Star | Interrogator | |
| Nicholas Renton | Director |