Guest Stars Victoria Pugh as DSI Susan Lynn Garmon Rhys as PC Ryan Davies Lowri Izzard as PC Mari James Elodie Wilton as Nia Harris Sarah Tempest as Alys Mitchell Megan Llyn as Bethan John Lara Catrin as Lea Pryce Mali Ann Rees as Ffion Gwion Aled Williams as Tomos Elis Mari Rowland Hughes as Delyth Hughes Ieuan Watkins as Anuerin Llion Williams as University Lecturer Greta James as Mali Pryce Gaynor Morgan Rees as Agnes Tom Mumford as Rhodri Moss