Supernova burns with love at the last

▶︎ Supernova is in cinemas from 25 June.

A lovely, semi-abstract sequence opens Harry Macqueen’s San Sebastian Film Festival premiere, Supernova. A dark sky lights up, star by star, in time with a single repeated piano note. With every key strike, more points of light appear; one shines brighter than the rest, briefly, then winks out. A hand resting on a naked torso twitches absently, also in time with the music – it’s as though, in sleep, the fingers are picking out a tune that plays whole galaxies into and out of existence a billion miles away.

The film will not always be this subtly allusive – sometimes it will fill out a melody that might have been better left as a half-remembered motif – but mostly this is the perfect induction into Supernova’s delicate connection-making, between the very close and the unreachably distant, the seismic and the minute.

The pianist is Sam, played by a beautifully modulated Colin Firth using his natural diffidence to devastating effect in a career-best performance. And the man he is cradling under tangled bedsheets is Tusker – an unlikely yet obscurely appropriate name for an American novelist – also perfectly played with that softly sarcastic sophistication that maybe only Stanley Tucci can deploy. But if the two performances are individually excellent, it is the relationship between them that is the real star of Supernova, a portrait of the dazzling starburst of intense feeling that floods a deeply loving couple’s universe right before heat death.

They are on a camper-van road trip through the Northern English countryside – shot with DP Dick Pope’s eye for the humble amid the grand: the inherently jaunty little van wending its way through hillscapes so vast there are shadows of entire cloud formations on their slopes.

But Tusker is gravely ill, and his disease brings with it periods of forgetfulness and disorientation. He loses words, and sometimes his bearings, but the cruelest aspect of dementia is that it doesn’t happen all at once, and Tusker is more often lucid than not, and heartbreakingly aware of all he is going to lose. He masks his terror well, for the sake of his beloved Sam – as the more gregarious of the two, naturally it is Tusker who harbours the biggest secrets.

Journey’s end is a concert Sam is giving – his first in a long time – but en route, after some relatable bickering about the satnav, the pair stops off with Sam’s sister Lil (Pippa Haywood), for a party she and Tusker have secretly arranged. It’s a merry occasion, but then Sam makes a shocking discovery when he opens the box in which Tusker keeps his writing paraphernalia, which is marked with his initials but might as well be engraved ‘Pandora’.

Occasionally, an overly literal music cue or a slightly contrived screenwriting device (there’s an Elgar piano concerto that is Tusker’s favourite and yet Sam has never played it for him) threatens sentimentality. But the palpable chemistry between the two graceful stars always brings the film back to the real, with Firth and Tucci exchanging the warm, witty dialogue with lived-in ease. Even so, it’s the unspoken language of this extended farewell that is most convincing – how death reverses itself into life, how every new moment instantly becomes a memory, browning at the edges like an autumn leaf.

Supernova is not an edgy film, scarcely alluding to the struggles this older gay couple undoubtedly faced along the way – one casual jab about Margaret Thatcher is as much political commentary as it contains. And due to Tusker’s illness and the long-worn familiarity of their closeness, but also to filmmaking restraint, the sole lovemaking scene is tender to the point of timid. But this gentleness and quietness is also the point, magnifying and universalising Macqueen’s eloquent, compassionate, moving drama: a supernova is the most traumatic and majestic of galactic events, but it happens in silence.