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 Steven Meo as DI Paul Stokes Meera Syal as Elizabeth Churchland Clive Russell as Clifford Major Richard Ayoade voices The Voice of Brian Colin McFarlane voices The Voice of Bad Brian Lara Cooper-Chadwick as Bomb Suspect