The film narrates the story of the discovery of the first glass-melting furnaces in Egypt, dating from the beginning of the Roman era. Based on research in archives and libraries, a pedestrian survey was launched in the region of Alexandria and in the oasis of Wadi Natrun. The first glass factories were found in this oasis. Excavations carried out by Marie Dominique Nenna and her team since 2003, led to an astonishing discovery: the biggest glass-melting furnace in the Antiquity. The glass plates that were produced could be of 15-20 tonnes each.