A disturbing scene presents a way forward in the investigation for Nikki and Jack. Professor Cherry continues to spiral, but who will he take down with him?
| Name | Type | Role | |
|---|---|---|---|
| Timothy Prager | Writer | ||
| Diveen Henry | Guest Star | Elaine | |
| Richard Keep | Guest Star | Harrison Cairney | |
| Kevin McNally | Guest Star | Professor Peter Cherry | |
| John Thomson | Guest Star | DI Warren Bull | |
| Maeve Courtier-Lilley | Guest Star | Vanessa | |
| Emily Piggford | Guest Star | Professor Elizabeth Newport | |
| Ashley Margolis | Guest Star | Haidar Alam | |
| Kaye Wragg | Guest Star | Valerie Fullerton | |
| Isobel Wood | Guest Star | Celeste Locke | |
| Tracey Rooney | Director |