Michael (Ewan McGregor) works as a chef in an up-market restaurant. He clowns around with his co-workers in the kitchen and has one-night stands with women. One of the signs of his trouble with relationships is that he can't sleep if anyone else is in the bed.

Susan (Eva Green) is a chilly epidemiologist who resides in a building near the restaurant. She doesn't have much time for dating. But eventually, Susan lets her guard down, and these two get together.

Susan and the doctors who work at her laboratory are baffled by a man who had an emotional breakdown and plunged into despair. Then a strange thing happened to him: he has lost his sense of smell. Soon reports are streaming in from around the world about a pandemic of emotional crises followed by a loss of smell. Scientists don't know whether this is being caused by toxins, the environment, or terrorists. The mysterious disease is named Severe Olfactory Syndrome (S.O.S).

Despite the widespread fear, people still go to work and carry on their daily lives as best they can. Michael cooks Susan a meal but in the midst of eating, she is overcome by grief. He takes her home and spends the night. By morning, they have both lost their sense of smell. Later, on the street, they are entranced by a creative violinist who has fashioned a mini-drama affirming the capacity of everyone to live with only four senses and still find wonder in nature and elsewhere.

As the disease progresses it knocks out the senses, one by one. Susan is overcome by terror in a parking garage and a woman offers solace. Then moved by hunger they devour whatever is in sight or reach: Susan eats the flowers the woman has bought, and her companion scarfs down her lipstick. At the restaurant, Michael and the other chefs are caught up in the same syndrome which ends with a lost sense of taste.

Trying to survive and make-do in this nightmarish atmosphere is a real challenge. Susan and Michael turn to the sense of touch in making love repeatedly. At work, the texture rather than the taste of food is emphasized.

The chaos, violence, and destructiveness escalates in Glasgow and in cities across the world. Susan moves in with Michael but is driven away when he erupts into a hateful and scathing verbal attack on her before going deaf. He and other people who can no longer hear are ordered to stay in their houses where it is safe. On the streets, the anger of citizens has led to killing sprees and looting. A few brave souls are preparing for the next loss resulting in blindness.

Director David Mackenzie has created an astonishingly effective apocalyptic sci-fi thriller that essentially is a beautiful love story. As the world plunges further and further into disaster, the screenplay by Kim Fupz Ackeson draws a bead on the need for all survivors to have somebody to lean on for love and courage and support. The narration of this thriller provides a lyrical explanation to what is happening to people affected by the pandemic. But it does not slight the mystery at the heart of the catastrophe.

Perfect Sense is a deeply spiritual film that challenges us to be fully alive to the report of our senses and to live in the present moment which will never appear again.

Special features on the DVD include a behind the scenes featurette.