The BBC Two documentary series concludes tonight with Michael Sheen wrapping up his investigation into alleged toxic contamination in north Wales, meeting cancer patients who believe the now-defunct chemical company Monsanto is responsible for their illness. The piece is part of the Guardian's nightly TV guide, which also flags other notable broadcasts including a foundling-siblings documentary on ITV1 and a Jake Gyllenhaal film on Sky Atlantic.

At the centre of Sheen's exposé is a lagoon in Ruabon, north Wales, so contaminated that the barrels once containing dumped chemicals have rotted away, an area where children reportedly played until around 20 years ago. The final episode sees Sheen meet affected residents seeking accountability, though the article notes this proves an uphill struggle. Other picks in the guide include Race Across the World's Northern Ireland finale on Channel 4, ITV1's The Foundlings, Celebrity Hunted, and film choices Howards End and Nightcrawler.