Exploring the pivotal 1949 experience atop Switzerland's Grindelwald glacier that reshaped British modernist painter Wilhelmina Barns-Graham's artistic perspective for decades to come.

Featuring Tilda Swinton as the voice of Scottish painter Wilhelmina Barns-Graham, this feature documentary tells the story of a remarkable artist and a magnificent obsession. One day in 1949, a young Scottish painter climbed a Swiss glacier. The experience rewired her brain, and transformed her art. Barns-Graham was synaesthetic - associating letters, names and people with particular colours - and Cousins explores how her neurodiversity and her encounter with the glacier shaped her vision of the world. Born and raised in St Andrews, Barns-Graham was a member of the St Ives group of modernist artists, who lived in the Cornish seaside town from the Second World War onwards. The glacier paintings inspired by her experience in Switzerland were the breakthrough in her artistic career. Through a cinematic immersion into her art and life, the film explores themes of gender, neurodiversity, climate change, and the nature of creativity from youth to old age. Made with the support of the Wilhelmina Barns-Graham Trust, the film delves into her archives, private notebooks and diaries from her 65-year career. Two decades after her death in 2004, the film represents a major reassessment of Barns-Graham's life and work, and her place in 20th century art.