Guest Stars Anna Maxwell Martin as Kelly Major Amanda Payton as Dr. Alison Parfit Rosie Cavaliero as DCS Dennett Michelle Greenidge as DS Judith Papastathopoulos Tracy-Ann Oberman as Helen Chalmers Richard Gadd as Liam Cleasby Michael Armstrong as Officer Mike Steven Meo as DI Paul Stokes Precious Mustapha as Roxy Millikan Chris Kamara as Chris Kamara Miranda Heath as Dr. Nazia Rana