Raimund Gregorius teaches classical languages at a Swiss lycee, and lives a life governed by routine. One day, a chance encounter with a Portuguese woman inspires him to question his life - and leads him to an extraordinary book that will open the possibility of changing it. Inspired by the words of Amadeu de Prado, a doctor whose intelligence and magnetism left a mark on everyone who met him and whose principles led him into a confrontation with Salazar's dictatorship, Gregorius boards a train to Lisbon. As Gregorius becomes fascinated with unlocking the mystery of who Prado was, an extraordinary tale unfolds.