Marina is a young mother who is never quite certain that she really wanted children in the first place. She loves her toddler Marco with an almost obsessive fixation but she also despises his ability to force her to become someone she never imagined herself becoming. Her husband Mario does not and can never understand her feelings. Their love for each other is waning. So Marina takes Marco on an extended visit to the Italian mountains to escape what she feels is Mario's incessant nagging.

In a small town she rents the upstairs rooms in Manfred's house; he is a mountain man whose wife and children have recently moved out. Manfred was born and has always lived on the mountain. He is a guide who takes groups of city people up the ridges and along the tracks of "his" mountain to the lodge where he grew up and which his brother now runs with his wife and children. He is a taciturn man; loathe to speak, silent and aloof. He has always been this way, a quiet boy who became more reserved and distant when his mother left home to live in America with a man she met at the lodge, leaving her husband and three very young boys behind. Their father being an uncommunicative man, the three boys were left to look after themselves for the most part.

Marina struggles to manage Marco. He does not sleep or eat well and is very demanding, and he has yet to start talking. One day she is overwhelmed, and Manfred hears screaming; he breaks down their door to find Marco in a pool of blood and Marina huddled behind the kitchen door in shock. He manages the situation, taking Marco to the hospital and reporting his findings to the police; he is convinced that Marina has deliberately hurt Marco.

Manfred becomes obsessed with Marina and her child. He cannot leave her alone. He is suspicious and unrelenting in his insistence that she tell the truth about what happened that day in the kitchen. Marina in turn becomes obsessed with finding out about Manfred and what has caused him to become the man he is. Their attraction to each other is as strong as their mutual dislike.

Comencini has written a story of obsession in Marina and Manfred's tale. Marina and Manfred are seriously flawed characters, both vulnerable and yet unyielding in their beliefs and actions. Each of them has failed in their most important relationships, and their fear of new associations, or any new connections is palpable.

When the Night is a psychological drama which will keep the reader on edge throughout. Comencini's spare style is well suited to a story which is both disquieting and engaging.