SUPER STORY, ACTING AND DIRECTING

When one of two central characters in a road movie has early-onset dementia, the destination is never in doubt.

But Tusker (Stanley Tucci) and his long-term partner, Sam (Colin Firth), have some control over how they get there.

And Supernova’s unhurried pace gives them – and us – precious time in which to appreciate small, domestic moments, like bickering over the merits of paper maps versus sat nav devices.

This is especially important in a film that’s ultimately about letting go.

Staring down the barrel of a cruel prognosis, the couple have dusted off their trusty campervan to spend some quality time together before it’s too late.

Their carefully planned itinerary includes a visit to an isolated spot in the Lake District where they once camped together, early on in their rela- tionship, and a trip to Sam’s sister’s house, where a surprise party has been organised with friends and extended family.

But writer-director Harry Macqueen gives equal weight to those in-between moments, such as the roadside carpark where the couple expediently stop for the night and where Tusker becomes disorientated after deciding to take the dog for a walk.

The actor-turned-filmmaker relishes the comfortable crampedness of the couple’s well-loved campervan, embracing small details such as the foggy windows and the damp canine smell.

And he pauses long enough for us to register the significance of the couple’s habitual nocturnal embrace – Tusker and Sam’s 20-year relationship has weathered well with age.

Firth imbues Sam with a very English reserve and stoicism – the musician is determined to see this challenge through, even if he sometimes doubts his capacity to do so.

Tucci also keeps a tight emotional rein on his charismatic extrovert. His character’s illness tends to reveal itself in micro-details, such as the inability to pick up a glass, or a lost word.

At no point does either of these veteran actors overplay their hand.

Macqueen’s direction is similarly restrained. The landscape the two men drive through feels lived in rather than postcard perfect.

And while the galactic phenomenon from which Supernova takes its title might suggest a heavy-handed metaphor, even here Macqueen understands that less is more.

At heart, Supernova is a love story.

As Sam, Firth has a powerful speech in which he reveals the depth of his resolve.

Trouble is, the journey doesn’t follow the route he had expected.