A young man on his first day in a new enterprise. Gradually, we get to know his position and outlook on life. In parallel, a new space operation is launched: another small step in the utopic desire to understand the infinite. Tackling the idea of contemporary mythology, where self-made men and the conquering of space have supplanted the ancient heroes, Le jour ou j’étais perdu seduces the audience with ambiguity and continuous shifts of perception.