This gallery of everyday heroism and cowardice provides scenes from a new urban mythology: the psychotherapy of public transport.

Hugo Boris has just gotten a black belt in karate when he boards a commuter train and sees two people start to fight. Paralyzed and petrified, all he can do is sound the alarm. This episode stays with him, revealing a deep-seated fear: a mixture of shyness and helplessness. He will spend the next fifteen years jotting down in a notebook every instance he sees of fear reigning on public transport. But violence isn't all he witnesses: he also describes delightful encounters, touching moments of dialogue, funny bits of banter... Through these serendipitous or tragic moments, he deciphers a slice of contemporary mythology: public transport.