Guest Stars Oscar Unsworth as Rhodri Howells Harry Unsworth as Rhodri Howells Mark Lewis Jones as Steve Baldini Aneirin Hughes as Tom Howells Hannah Daniel as Cerys Jones Bradley Freegard as Evan Howells Catherine Ayers as Lisa Connors Alex Harries as Arthur Davis Demi Letherby as Alys Howells Eiry Thomas as DI Susan Williams Lacey Jones as Megan Howells Betsan Llwyd as Delyth Lloyd Rhian Morgan as Marion Howells Anastasia Hille as Gael Reardon Aimee-Ffion Edwards as Madlen Vaughan Rhashan Stone as DI Laurence Breeze Brochan Evans as Dyfan Vaughan Martha Bright as Angie Baldini Steffan Rhodri as Y Barnwr Gwyn Daniels Rebecca Harries as Hannah Lewis Alun ap Brinley as Geraint Jernigan Richard Lynch as Hayden Swancott QC Charlie Spring as Hyfforddwr Bocsio Morgan Hopkins as Gareth Tacsi Robert Gwyn Davin as Gard