Grief manifests itself in two ways: The first is when a lover breaks your heart,and the latter is when they die. As it happens,Una (Elín Hall) is experiencing both. Devastated by the sudden death of her paramour Diddi, she finds herself in an uncomfortable position when Diddi’s long-distance girlfriend Klara (Katla Njálsdóttir) – a woman he promised to break up with – arrives at the scene. She empathises with Klara, and elects to keep the news silent; she tells her father that her “friend” has perished. The two women could not be more different, and initial get on each others nerves, but after sharing a cigarette outside the memorial service, they gradually grow closer together, until Una realises that Klara reflects the other side of Diddi.

Gingerly directed, with a real appetite for authenticity, director Rúnar Rúnarsson avoids the edifices of cinema to bring something that is raw, revealing and deeply relatable. Wisely, he chooses to focus his attention on a group of college students: too old to be coddled by their parents, but too young to shoulder this passing with mature cognisance. Una confides to her friend that compared to Diddi’s demise, the death of her grandparents feels incidental. She distracts herself with cigarette puffs – much to her father’s bemusement – but Una’s wounds re-open when her friends offer Klara the hugs that should be aimed at her. “I was his girlfriend,” she screams; “not her.” But the more she tries to villify Klara, an adolescent who could never understand her boyfriend’s passion for performance art, the greater she empathises with her. In one strangely beautiful composite shot, Rúnarsson places Una and Klara at the opposite ends of a window, their faces melding into one gigantic hole of sadness and glee.

Schematically, When the Light Breaks could be described as Three Colours: Blue (Krzysztof Kieślowski, 1993) for college students, but that would do an injustice to the hopefulness that soaks to the second half. Klara likens Diddi’s funeral to a sunset waving goodbye to the people who loved him, the orange hues draped gently over the tranquil sea. Rúnarsson’s interest lies in the here and now: Una and Klara do not what they will do the day after the funeral, let alone in the months ahead. Rúnarsson is similarly more interested in establishing character development over plot, and the feature’s most interesting moments are the more spontaneous one. (Klara dances giddily to the sound of a rock-track, before being struck down by tears again.)

There are very few directorial flourishes, and for the most part, Rúnarsson puts the focus on Una. She directs the camera: the audience follows her to the streets, schools and chapels she enters. Once Klara becomes a more prominent fixture in the story, she takes charge, which is evident from the way the photography zooms closer and closer to the top of the church; mirroring Klara’s desire to fly over the building. Rúnarsson’s work is holistic in exhibition, but he permits himself one more interpolation, which is demonstrated during the opening credits as the camera drives along a darkened tunnel, before halting at a large explosion. The audience quickly works out what happened, but it takes Una – protagonist and pansexual bandmate – longer to work out the dreadful news. In many ways, the audience knows more than the characters do.

When the Light Breaks offers hope to two young women coming to terms with a shared loss. A beautiful journey, and a humbling experience.

Rúnar Runarsson’s fourth feature film opened the Un Certain Regard section of the 77th Cannes International Film Festival, when this piece was originally written. Also showing in the 58th edition of Karlovy Vary, and at the 68th Tallinn Black Nights.