| Respected police officer John River, a gifted cop with a troubled mind, struggles to come to terms with the recent loss of a colleague, and chases a suspect across London - with tragic consequences. Now at odds with the authorities, River ends up in a precarious position as he seeks to bring closure to the mother of murdered teenager, who blames him for failing to keep his promise. |
| Name | Character | Episodes |
|---|---|---|
| Stellan Skarsgård | John River | 6 |
| Nicola Walker | Jackie 'Stevie' Stevenson | 6 |
| Eddie Marsan | Thomas Cream | 6 |
| Lesley Manville | Chrissie Read | 6 |
| Sorcha Cusack | Bridie Stevenson | 6 |
| Adeel Akhtar | Ira King | 6 |
| Michael Maloney | Tom Read | 6 |
| Owen Teale | Marcus McDonald | 6 |
| Steve Nicolson | Jimmy Stevenson | 6 |
| Jim Norton | Michael Bennigan | 6 |
| Josef Altin | Christopher Riley | 6 |
| Georgina Rich | Rosa Fallows | 6 |
| Turlough Convery | Frankie Stevenson | 6 |
| Franz Drameh | Bruno Marconi | 2 |
| Helen Anderson | Tom's Lawyer | 1 |