Noah, a young man in search of his identity, is invited by his best friend, Ethan, to take part in the expeditions he organises with his gang in the depths of the metro. In this in-between world, where they compete to find their place, Ethan will challenge the teenagers to jump over the rails before the train arrives. For Noah, risking his life seems to be the only way to be accepted and above all to exist in Ethan's eyes.