David Mitchell John Taylor Actor, Executive Producer Anna Maxwell Martin Lucy Betts-Taylor Actor Dipo Ola DI Russell Carter Actor Sophie Willan Holly Pinder Actor Gerran Howell DC Simon Evans Actor Izuka Hoyle DS Alice Finch Actor Dylan Hughes Henry Betts-Taylor Actor Ralph Ineson Chief Constable Ziegler Actor Dorothy Atkinson DCS Carol Shaw Actor Suzanne Ahmet Gillian Botley Actor Natali McCleary Zara Bassett Actor Raychel Addo Police Officer Actor Sophie Allen Ms Chordwell's Interpreter Actor Gavin Spokes Connor Merton Actor Julie Dray Tanya Actor Robert Jarman Martin Symes Actor Julie Legrand Manon Actor Jakub Bednarczyk Young John Actor Yasmin Dacre Sasha Sparks Actor Mark Slaughter Jordan Halshaw Actor Mark Brotherhood Writer, Executive Producer Robbie McKillop Director Kenton Allen Executive Producer, Producer Jill Robertson Director Georgie Fallon Producer Saurabh Kakkar Executive Producer David Mitchell Executive Producer Kathryn O'Connor Executive Producer Chris Sussman Producer, Executive Producer