Special Guest Stars Ṣọpẹ́ Dìrísù as Sean Donovan Katherine Waterston as Alison Dunn Guest Stars Rosalind Eleazar as Louisa Guy Saskia Reeves as Catherine Standish Christopher Chung as Roddy Ho Chris Reilly as Nick Duffy Aimee-Ffion Edwards as Shirley Dander Kadiff Kirwan as Marcus Longridge Eliot Salt as Sarah Dunn Charlie Rowe as Ben Dunn Sion Daniel Young as Douglas Co Starring Bally Gill as Agent Singh Roli Okorodudu as AA Chairperson Henry Davis as Louisa's Pickup Simon Chandler as Doctor Caroline Harker as Doctor's Receptionist Bradley Connor as Lad in Kebab Shop Fırat Doğruloğlu as Alison's Contact Will Bowden as Taverner's Driver Azaan Symes as Kebab Shop Man George Turvey as Husband Selahattin Çakir as Water Taxi Driver 1 Ömer Faruk Ertuğrul as Water Taxi Driver 2 Connor Porter as Lad in Kebab Shop Esme Allen as Barista Caz