It is during a night in a post-reconstruction world that a masked call rings out. Cheikh Morad Djadja wanders through these non-places in search of an anonymous telecommunication space. This universe with its illusory and oppressive walls, makes us notice the existence of an abstract space-time in which a trans-identity tries to find a place. #31# (appel masqué) is a proposal halfway between documentary, fiction and installation, exploring the hidden meaning of a coded message, this one coming from a literary/musical genre, the raï.