Four species of animals are used in this movie: a cat, a dog, some cows and a ferret. The last one was a late option from the director while he was looking for a rabbit. His intention was to put some animals as spectators of the human actions.
While a crime is being planned at a restaurant, Ricardo Sá Fernandes enters and is welcomed by some customers. He is a criminal lawyer, author of the book "O Crime de Camarate" (April, 2001), on the subject of director's Luís Filipe Rocha docudrama Camarate (2001).
Cinzento e Negro (Grey and Black) is an allusion at Stendhal's The Red and the Black, but also the principal colours of the land in Pico island.
Maria das Dores have a protestic shoe. Nothing in the story justify this infirmity. The director chose this character after seeing a woman with this type of shoe in real life, carrying shopping bags while her companion was walking by her side, just smoking. This character is a kind of revenge for this anonymous woman.