Onwards and Sideways began, improbably, with a sheepdog herding people through a dance class in Bangor. Rhys Ifans attended weekly Parkinson's movement sessions at Pontio arts centre in north-west Wales, where a harpist played and a stray sheepdog worked the room. Laura Linney, meanwhile, found her way to the Mark Morris Dance Group in Brooklyn, where choreographer David Leventhal runs Dance for PD — the programme she calls 'the mothership' of a global network. Both actors arrived on set having watched what happens to a body when the music stops. 'It's shattering,' Linney says, 'in a good and a sad way.' The film, directed by John Madden — whose credits run from Shakespeare in Love to Mrs Brown — is set in Norfolk and written by Paul Mayhew-Archer, co-creator of The Vicar of Dibley and a Parkinson's diagnosis at 58. His neurologist told him he seemed to have difficulty smiling. He replied that this might be because the neurologist had just told him he had Parkinson's. The joke is in the film. So is the compulsive gambling, a known side-effect of the dopamine-agonist drugs used to manage the condition — Linney's Emma has bankrupted herself. So is the night-terror violence: Ifans's Tony nearly throttles her in his sleep. Neither actor did a chemistry read before shooting. They went straight to the material — which required Linney to collapse weeping in Ifans's arms and Ifans to physically embody a condition the pair describe as a 'physical dialect'. The Neuro Heroes, physiotherapists specialising in Parkinson's and related conditions, helped them with what was happening at the muscular and skeletal level. But they needed, as Ifans puts it, poetry too: 'Whether it felt like moving through tar or sand.' Physicality as language, learned from scratch. Mayhew-Archer's writing is clear-eyed about why two non-disabled actors were cast in the central roles. His character Emma undergoes a procedure that causes certain symptoms to cease. 'It would be very hard for people with Parkinson's to stop doing some things,' he notes with the precision of a man who has thought about this carefully. 'Once you start freezing, you can't stop.' The pragmatic honesty is characteristic of the whole enterprise: funny and devastating in equal measure, which is Mayhew-Archer's explicit programme. He saw no point in being serious about it. Linney, 62, comes to this from a career that runs from The Truman Show through Mystic River, Love Actually, Ozark, and The Big C — a filmography organised around women in extremis, often played with a stillness that reads as concealment. Ifans, 59, broke through in the Welsh Twin Town, made his mark on mainstream consciousness as the scraggly Spike in Notting Hill, and has spent the years since in roles from Daniel Craig's stalker in Enduring Love to drug smuggler Howard Marks in Mr Nice. These are not actors who coast. What the piece captures is two people who found, in the shared responsibility of getting Parkinson's right, something that accelerated trust past what any chemistry read could manufacture. 'I couldn't tell you what kind of car Laura drives,' Ifans says. 'But we both know how we feel about death and dying.' Linney is currently filming the DC series Lanterns (as a Guardian of the Universe, she will say no more) and the Colin Firth/Julianne Moore romcom Comfort and Joy, about the north London throuple behind Alex Comfort's 1972 sex manual. Ifans was, at time of interview, being beheaded in House of the Dragon. Onwards and Sideways sits at the opposite end of every production spectrum: no high concept, no CGI, no swords and castles. 'You ain't gonna have a co-star like this,' Ifans says, beaming at Linney. 'That's where the money is. Not the coin.' In the UK, 166,000 people are currently living with Parkinson's, with one new diagnosis every 20 minutes according to Parkinson's UK. This film was made for them first. Whether it also makes for essential television for the rest of us depends on your appetite for work that treats a difficult subject with enough craft and dark humour to be both honest and bearable — which is, it turns out, harder to do than most prestige drama pretends.
