Ernesto is a successful painter. He is separated from his wife Irene, mother of his beloved young son Leonardo. One day he is informed by the enigmatic Don Pugni (Cardinal Piumini's secretary) that his mother is in the process of being made a saint. Ernesto is stunned by this news because his family has not mentioned anything to him about it and because it contradicts everything he believes in as an artist and an atheist. The memory of his mother (and her beguiling smile) and the presence of a strange and beautiful teacher of religion open a whirl of unespected events through which Ernesto must revise his view of the past and face the present in a new way.