Guest Stars Alison O'Donnell as DS 'Tosh' MacIntosh Steven Robertson as DC Sandy Wilson Lewis Howden as Sgt Billy McCabe Mark Bonnar as Duncan Hunter Erin Armstrong as Cassie Perez Julie Graham as Rhona Kelly Neve McIntosh as Kate Kilmuir Fiona Bell as Donna Killick Stephen Walters as Thomas Malone Sean McGinley as Drew McColl Sophie Stone as Jo Halley Gerard Miller as Alan Killick Gayle Watson as Mary Hunter Carolin Stoltz as DI Anke Strom Arnmundur Björnsson as Lars Bleymann Eleanor Matsuura as DI Jessie Cole Tony McGeever as DS Ian Jackson Amy Lennox as Sally McColl Nathan Welsh as Robert Downing