“Supernova” is a little somber drama which depends a lot on the undeniable chemistry between its two lead performers, who are simply fabulous as playing along with each other throughout the film. As their characters interact more and more on the screen, we come to sense more of many years of life and love between their characters, and that is the main reason why its rather contrived finale works on the emotional level.

Colin Firth and Stanley Tucci play Sam and Tusker, a middle-aged gay couple who are starting the first day of their road trip along the rural areas of England at the beginning of the movie. While Tusker is an acclaimed novelist, Sam is a fairly well-known pianist, and they decided to have a little private trip for them before Sam gives a small concert performance at the eventual arrival point of their road trip.

As they talk with each other during their driving time, we get to know more of how Sam and Tusker complement each other in their palpable personality difference. While Sam is your average reserved British gentleman, Tusker is a fastidious American dude who usually insists on getting things done in his ways, and we are amused to see them arguing a lot on whether they are driving in the right direction now. Although he gets more annoyed, Sam does not mind this at all because 1) he has apparently been accustomed to living with his spouse’s flaws while always loving him for who he is and 2) he is reminded again of how Tusker is still himself despite going through the early stage of dementia at present.

However, Sam cannot help but concerned about his spouse’s medical condition, which has been irreversibly deteriorated day by day no matter how much they try to hold each other. At one point where they are at a place where they are supposed to spend a night, Sam suddenly finds that Tusker is gone along with their pet dog, and he frantically looks for Tusker until Tusker is eventually discovered at a nearby spot with the dog while visibly quite confused about his current status.

And this incident makes both Sam and Tusker reflect more on how much their relationship will be affected by Tusker’s worsening condition. Sam is already determined to stand by Tusker, no matter how his dear spouse’s mind will be faded during next several years. In contrast, Tusker does not want more pain and suffering for himself as well as Sam. He is already losing his ability to write, and that makes him wish more for some dignity and control for his remaining years, which are bound to be accompanied with much more dread and confusion of losing himself.

At least, both Sam and Tusker are still consoled by each other’s presence. They drop by a serene remote spot where they met each other for the first time a long time ago, and they cannot help but become a little nostalgic about many years they have spent together. When they subsequently come to stay at a house belonging to the family of Sam’s sister, Tusker has a little surprise for Sam, and that culminates to a heartfelt moment when Tusker attempts to read something special for him and his spouse.

However, Tusker’s gradually fading mind still remains as a gloomy fact looming over him and Sam, who becomes more conflicted when he later comes to find something Tusker has not told him yet. As a result, the third act of the screenplay by director/writer Harry Macqueen becomes more tense and serious, and that is where the movie tries to pull our heartstrings a little too hard. To be frank with you, the finale is a bit manipulative, and the ending is also too abrupt compared to what has been so carefully built up during the rest of the story.

Nevertheless, the movie is still engaging thanks to the solid performances from Firth and Tucci, both of whom never make any misstep as flawlessly revolving around each other. While Firth, who has been always good at expressing understated feelings and thoughts beneath the surface, ably conveys the growing pain and despair churning behind his character’s calm façade, Tucci, who has always been dependable since I came to notice him for the first time via “Big Night” (1996), is equally superb as subtly articulating his character’s fear and concern without any ounce of exaggeration, and their fluid interactions give us intimate glimpses into a long and loving relationship which has endured so many years but will inevitably be ended sooner or later.

Macqueen wisely lets his two lead actors take the whole stage while steadily maintaining the quietly elegiac mood in the background. Thanks to cinematographer Dick Pope, the movie occasionally gives us a series of gorgeous landscape shots to be appreciated, and these lovely moments in the film accentuate more the bittersweet sense of love and loss surrounding Sam and Tusker.

Although it is instantly compared with many other similar drama films ranging from “Iris” (2001) to “Still Alice” (2014), “Supernova” is worthwhile to watch mainly for Firth and Tucci. What they do here looks modest at first, their result glimmers as much as the very title of the film suggests, and you may get some valuable lessons on love and relationship from that.