“It will be difficult to find two better performances than these two acting veterans this year.”

Death is coming for us this cinema summer. From Pablo Larraín’s account of the last week of Maria Callas’ life to Tilda Swinton quietly fading out on a lounger in Pedro Almodóvar’s The Room Next Door, finality is back with a vengeance. And as fate would have it, another Spanish director follows in Almodóvar’s footsteps, with Carlos Marqués-Marcet’s own take on euthanasia They Will Be Dust (Polvo Serán). A sober but deeply honest and heartfelt look at not just suicide, but how it tests the strength of a relationship as well, the film at unexpected moments breaks out of its misery with a bit of song and dance, to mixed success. But with a pair of towering performances at its heart, this earnest story of two people who don’t believe in ’till death do us part’ will move even the most cynical.

Claudia and her longtime partner Flavio (acting titans Ángela Molina and Alfredo Castro respectively) are not willing to meekly await Claudia withering away from an incurable illness, a grave condition that will end in the unavoidable. Rather than being parted by the bitter end, their plan is to speed things up and end their lives together in Switzerland, a country where assisted suicide is legal. They arrange a hasty wedding, after all those years together, much to the confusion of the children they are about to leave behind. That confusion turns to sadness and anger once Violeta (Mònica Almirall Batet), their eldest, and her siblings find out about their parents’ plan. Violeta unwillingly becomes a go-between for her parents and the world that they are about to leave behind. She accompanies them to Switzerland, to a sad little house in an industrial zone where Claudia and Flavio intend to take their last breath together.

At its heart, this austere ensemble drama revolves around the elderly couple and how they navigate their impending, self-inflicted death, and how this idea affects their relationship. Both stage actors, with her also having a history in dance, they both feel as if they have gotten the most out of life; she doesn’t want to go on with the pain, he doesn’t want to go on without her. His decision to join her in eternity causes the expected strife and doubt, but also moments of tenderness and a deeply felt love for each other.

And then there are the musical parts. At various points in the film, and invariably centered around Claudia, They Will Be Dust will turn into a musical, with contemporary dance choreographies and mostly harmonious vocalizations pushing the character forward through different stages on her path to death. While in isolation these scenes are well put together, and even in the moment where Violeta sings, they feel incongruent with the minimalist drama that surrounds them. It is as if Marqués-Marcet felt that the lack of melodrama at the core of his film needed a counterweight. Unfortunately the interjections don’t work at all, and are irritating intermissions in a beautiful elegy on two people who are so deeply connected they are not willing to either leave or be left behind.

Those two people are portrayed with a strong sense of humanity and a touching brittleness by Castro and Molina, both at the top of their game; it will be difficult to find two better performances than these two acting veterans this year. Every small gesture, every minute change in facial expression, every modulation in body language creates not just two lived-in characters but an utterly believable relationship, a vulnerable but strong bond between these people who have been together for decades. The two actors display a naturalism and command of their craft that would be a joy to behold if the subject matter weren’t so sad. The rest of the cast follow suit, but outside Almirall Batet they get only a few scenes to play with.

The clashing tones of the dramatic main narrative and the more lighthearted interludes is something They Will Be Dust cannot overcome. The dance sequences break up the flow of the film and fail to fully contextualize the tale that they intend to adorn. A shame, because the main story is, while small, a perfectly put together example of adult drama that deals with difficult subject matter in a respectful manner. While the premise of two parents deciding to say their last farewells together may not be common, these conversations about death and euthanasia in families in which a loved one is terminally ill are relatable. Brought to life by an excellent cast led by two phenomenal performances by Castro and Molina, They Will Be Dust feels like a missed chance at having a small gem on our hands. As it stands, the film’s uneven tone can leave you frustrated, longing for Claudia and Flavio’s downbeat death march whenever another upbeat piece of musical theater comes along.