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 Richard Gadd as Liam Cleasby Michael Armstrong as Officer Mike Steve Oram as DI Gilbert Emily Lloyd-Saini as DI Ryle Steven Meo as DI Paul Stokes Clive Russell as Clifford Major Beau Fowler as Pigtails Richard Ayoade voices The Voice of Brian Precious Mustapha as Roxy Millikan