As the son of two inmates Hyacinth was always more at home in prison than in the outside world, until he took part in a foot race that promised to change his life.

Giacinto was born in jail: he lives through his childhood there with his mother. Prison is where he learns how to walk, or rather run. When he gets "released" due to a law, a big jail guard called Jack walks him out. He's a grouchy but kind man. A young, energetic and patient priest, Father Aldo, welcomes Giacinto to a foster home, where he feels he just doesn't belong and gets bullied. To him, prison is the best place to run and hide from such a dangerous and unknown world. Whenever he can, he rushes to his mom... until she's gone. He goes back in as an adult since he becomes a prison officer: Jack is still there, so Giacinto gets to really know him - both in a positive and negative way. However, getting close to the inmates will get him into trouble: how can he run in a true marathon when he's on house arrest in the jail's lodgings?