Leo Castaneda is Spanish, he lives in Brussels, where he drives line 6 metros. One evening, he catches the eye of a young man at the edge of the platform. Feverish eyes of distress, a familiar face... Leo recognizes his son Hugo when he tragically disappears on the tracks! Leo, who had not seen him for more than two years, will discover that Hugo was involved in a bloody robbery. He will have to face violent criminals to try to understand the reasons for the death of his son.