Hidden (2018)

North Wales gets its own brooding detective, and Snowdonia's woods and quarry towns make a colder, harder backdrop than the south's coastlines. Siân Reese-Williams and Siôn Alun Davies are a well-matched pair of detectives, and the second series moves the case into slate-gray Blaenau Ffestiniog. It went out in Welsh on S4C as Craith, then as Hidden in a bilingual version that's mainly English. Learners will enjoy hearing both languages sit side by side the way they do in Gwynedd. Three series, with a definite ending.