[8] The film tells a story of Mariana, a nurse who leaves Lisbon to accompany an immigrant worker in a comatose sleep on his trip home to Cape Verde.
Cryptic ellipses, cinematographic precision, narrative abstraction and lingering imagery of people and place, notably Mount Fogo, the highest active volcano of Cape Verde, are features in this melancholic meditation on love and loneliness.
In an interview with Jean-Pierre Gorin, Costa has stated that Casa de Lava was the gateway to making his films in Fontainhas.
When he left Cape Verde after filming, many people gave him letters or presents to deliver to their friends and relatives back in Lisbon.
Costa went to the shantytown of Fontainhas to deliver the letters and became enraptured with the environment, its smells and sensations (which he called spicy).