The discussion which follows has the aim to bring explanations on the subject of the Diasporas in Cairo, their transit and their settlement in and via the Egyptian capital. Indeed, whereas the majority of the studies made in this field concern the populations themselves, it appeared interesting for us to highlight more discrete, and therefore less analyzed aspects, i.e. the general problems of the migratory transit of the refugees and migrants in the city. In particular we were interested in the devices set up to accommodate them and in the actors behind this process. We have consequently decided to have a discussion with a catholic priest, Father Aldo Berardi of the Trinitary Order. It was an occasion to continue a dialogue that had begun at an earlier time, when Father Berardi described us his experience as a priest in a Sudanese community of Cairo, and to look further into the way in which this action makes sense within the apostolic action of the catholic Church.