This Cuban film by Humberto Solas, creates a filmic equivalent of a musical cantata. It uses poetry, music, myths and historical reconstructions to put the case against foreign exploitation of Latin America, from the period of the Spanish conquistadores to the British mining companies.

The central theme of the film is the strike in a British-owned Chilean nitrate mine in 1907. Troops were brought in, and more than three-and-a-half-thousand of the striking workers were massacred This event is seen in the light of earlier episodes from Chilean history, and serves to illustrate a continuing history of violence and repression.

The poetry of Pablo Neruda, folk songs, and the original musical score form an integral part of the film.