Guest Stars Orla Brady as Catherine Sinéad Cusack as Meg Tobias Menzies as Raymond Sacha Dhawan as Vincent Dan Li as Hatsuto Nigel Whitmey as Lowe Molly Jones as Scarlet Vera Filatova as Svetlana Tom Wlaschiha as Arkady Antonia Thomas as Maddy Ron Donachie as Sturridge Simon Donald as Dr Christianson