Episode 1 When the body of a teenage girl who went missing at the turn of the millennium is found at a building site off the M1 motorway, four men are placed under the spotlight and their relationships are tested to the limit. Details Casts Videos Galleries Posters Season Lists Title Episode 1 Genres Drama Crime Mystery Release Date 2018-07-15 Episode Runtime 00 Hours 46 Minutes Season Number 3 Episode Number 1 Production Companies Mainstreet Pictures Nicola Walker... DCI Cassie Stuart... Sanjeev Bhaskar... DS Sunil 'Sunny' Khan... Carolina Main... DC Fran Lingley... Jordan Long... DS Murray Boulting... Lewis Reeves... DC Jake Collier... Peter Egan... Martin... Alastair Mackenzie... John Bentley... Elliot Morris... Asif... Tom Rhys Harries... Elliot Hollis... Siobhan Redmond... Derran Finch... Sara Stewart... Mel Hollis... Kevin McNally... James Hollis... Brid Brennan... Suzanna Reid... James Fleet... Chris Lowe... Indra Ové... Maria Carr... Emma Fielding... Amy Hollis... Gerald Kyd... Adrian Mullery... Unforgotten | ITV (Trailer) Unforgotten | Series 1 | ITV (Trailer) Original Size (1280x720) Original Size (1920x1080) Original Size (3840x2160) Original Size (2560x1440) Original Size (1920x1080) Original Size (3840x2160) Original Size (3840x2160) Original Size (3840x2160) Original Size (1920x1080) Original Size (1920x1080) Original Size (1920x1080) Original Size (1920x1080) Original Size (3840x2160) Original Size (1920x1080) Original Size (1920x1080) Original Size (960x1440) Original Size (960x1440) Original Size (670x1005) Original Size (1000x1500) Original Size (680x1000) Original Size (1000x1500) Original Size (680x1000) Original Size (680x1000) Original Size (680x1000) Original Size (2000x3000) Original Size (1000x1500) Original Size (2000x3000) Original Size (720x1080) Original Size (1055x1500) Original Size (680x1000) Original Size (1333x2000) Season 1 6 Episode(s) 2015-10-08 Season 2 6 Episode(s) 2017-01-05 Season 3 6 Episode(s) 2018-07-15 Season 4 6 Episode(s) 2021-02-23 Season 5 6 Episode(s) 2023-02-27