Guest Stars Harry Unsworth as Rhodri Howells Oscar 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 Rhian Morgan as Marion Howells Celia Imrie as Rose Sion Daniel Young as Gareth Siân Phillips as Barnwr Owens Maria Pride as Julie Penry Isaiah Cai Forrest as Lewis Kev McCurdy as Joe Price Keogh Kiernan as Osian Rachel Cheung as Rheolwraig Y Gampfa Marc Antolin as Athro Rhys Matthew Aubrey as Mike Taylor