Twins have proved a fine addition to many horror films, most notably the Shining, and a handy comic trope in both The Parent Trap and, well, Twins. With a few notable exceptions – Wanda and Pietro Maximoff in Avengers: Age Of Ultron spring to mind – brother and sister twinships are seldom spotted, let alone explored, in the movieverse.

My Little Sister, the second feature film from Swiss writer-directors (and documentarians) Stéphanie Chuat and Véronique Reymond and Switzerland’s entry for this year’s Academy Awards, features the great Nina Hoss as Lisa and Lars Eidinger as Sven, siblings who were born minutes apart.

Lisa’s career as a talented playwright is on hiatus to facilitate a gilded Alpine life with her children and husband; the latter teaches at an impossibly snooty boarding school at a ski resort. Sven’s career, meanwhile, is on hold while he receives treatment for cancer.

Lisa, who is simultaneously motherly and furiously compensating, is determined to nurse her gay, leukaemia-afflicted brother back to health and onto a stage. It’s a big ask of a woman who is already snowed under with maternal and domestic responsibilities and expectations. “I have plans too,” she tells her husband Martin (Danish actor Jens Albinus), who seems to have never considered such a possibility.

Barring one thrilling parasailing sequence, cinematographer Filip Zumbrunn maintains an intimate, handheld gaze on Hoss as her buttoned-down frau becomes visibly frazzled.

The script’s bumpy naturalism – including Lisa’s all-night rewrite of Hansel and Gretel – makes for some uneven moments. Hoss and Eidinger, however, spark off one another, electrifying lines and scenes that might not have otherwise worked. The emotional pyrotechnics that scaffold most cancer dramas, give way to something that is as honest as it is understated. When Lisa finally breaks, it is to feebly kick a recycling bin, a scene Hoss plays for tragedy, humour, and everything in between.