Las poquianchis (De los pormenores y otros sucedidos del dominio público que acontecieron a las hermanas de triste memoria a quienes la maledicencia así las bautizó) (1976)

The film is based in a true-life story; nasty and ugly as possible, since it involves a ring of child and women prostitution in which some middle-rank politicians and police bosses in mid-cities in Central Mexico (El Bajío) were involved from the early 50's to the early 70's.

The film keeps almost always a closed, dark atmosphere, which can be suffocating, but reflecting accurately the kind of life the girls in this ring were living as forced prostitutes.

The film has several twists; one of the most interesting is the fact that the ring was headed by two women (Las Poquianchis) who presented themselves publicly not as the regular brothel happy-go-lucky "madame", challenging the status quo, but as faithful Catholics. Another key twist is, of course, that of the involvement of the local authorities in the cities where Las Poquianchis operated their ring.

Overall, it is a very good under-rated and under-appreciated Mexican movie.