Guest Stars Kingsley Ben-Adir as Dr. Marcus Summer Robert Glenister as Owen Preece Billy Howle as Billy Shearwood Colin Tierney as Luke Shearwood Tim Dantay as Mark Donovan Clare Kerrigan as Gemma Makins Maibritt Saerens as Stella Shearwood Co Starring Olivia Armstrong as Jessie Ashworth Martin Oldfield as Solicitor John Draycott as Cawley & Griffin Tailor Moey Hassan as Malachi Melissa Sinden as Eileen Agata Jarosz as Cleaning Lady Tom Hutch as DC John Warren Ian van Temperley as John Shearwood