Episode 4 Iona's temper worsens as she punishes Nia and the police visit Dylan to question him. Details Casts Videos Galleries Posters Season Lists Title Episode 4 Genres Crime Drama Mystery Release Date 2018-01-28 Episode Runtime 00 Hours 57 Minutes Season Number 1 Episode Number 4 Production Companies Severn Screen Sian Reese-Williams... DI Cadi John... Sion Alun Davies... DC Owen Vaughan... Rhodri Meilir... Dylan Harris... Victoria Pugh... DSI Susan Lynn... Lowri Izzard... PC Mari James... Garmon Rhys... PC Ryan Davies... Elodie Wilton... Nia Harris... Gwyneth Keyworth... Megan Ruddock... Gillian Elisa... Iona Harris... Nia Roberts... Elin Jones... Ian Saynor... Huw John... Hidden: Trailer - BBC (Trailer) Original Size (2048x1152) Original Size (1920x1080) Original Size (1920x1080) Original Size (1600x900) Original Size (3840x2160) Original Size (1920x1080) Original Size (1712x964) Original Size (3840x2160) Original Size (3840x2160) Original Size (1920x1080) Original Size (720x1080) Original Size (720x1080) Original Size (800x1200) Original Size (2000x3000) Original Size (1200x1601) Original Size (680x1000) Original Size (680x1000) Original Size (2000x3000) Original Size (2000x3000) Original Size (2000x3000) Original Size (2000x3000) Original Size (2000x3000) Original Size (960x1439) Original Size (1280x1920) Original Size (1014x1520) Season 1 8 Episode(s) 2018-01-07 Season 2 6 Episode(s) 2019-11-17 Season 3 6 Episode(s) 2021-10-10