"Porta de Expressão" begins with a shot of the stairs at the entrance to the Cineclube de Guimarães. The sound of footsteps ascending the stairs and the murmur of a small crowd fill the air, but the stairs are empty. This "phantom sound" creates an atmosphere of mystery and absence, reflecting the invisibility and silence forced by censorship. The subtle sound of the projection machine mixes with some voices that tell of the many creative ways that the film society found to circumvent censorship during the PIDE era. Among the many cinephile memories there are reports of the cultural resistance of the film club.

After the Carnation Revolution, Portugal became a democracy and opened itself to the world. One of its consequences was the spread of erotic and pornographic films. This documentary tells the story of how these films arrived at Theatro Gil Vicente, an emblematic cultural venue of Barcelos.