| Name | Character | Episodes |
|---|---|---|
| Rufus Sewell | Lucas Romer | 2 |
| Hayley Atwell | Eva Delectorskaya | 2 |
| Michelle Dockery | Ruth Gilmartin | 2 |
| Charlotte Rampling | Sally Gilmartin / Eva Delectorskaya | 2 |
| James Norton | Kolia | 2 |
| Michael Gambon | Baron Mansfield / Lucas Romer | 2 |
| Alexander Fehling | Karl-Heinz | 2 |
| Gwilym Lee | Sean Gilmartin | 2 |
| Adrian Scarborough | Morris Devereux | 2 |
| Julian Firth | Club Servant | 2 |
| Bertie Carvel | Mason Harding | 2 |
| Anthony Calf | Gerald Laird | 2 |
| Angus Imrie | Student | 2 |
| Dominic Rowan | Detective Sergeant Mason | 2 |
| Stephen Jennings | Man | 2 |
| Tom Brooke | Angus Woolf | 2 |
| Edwin Thomas | Edward | 2 |