He will stay like this forever, Robert's arm draped round him. They will be forever twenty.

Scotland, 1933. Bobby MacBryde is on his way. After years grafting at Lees Boot Factory, he's off to the Glasgow School of Art, to his future. On his first day he will meet another Robert, a quiet man with loose dark curls - and never leave his side.

Together they will spend every penny and every minute devouring Glasgow - its botanical gardens, the Barras market, a whole hidden city - all the while loving each other behind closed doors. With the world on the brink of war, their unrivalled talent will take them to Paris, Rome, London. They will become stars as the bombs fall, hosting wild parties with the likes of Lucian Freud, Francis Bacon and Elizabeth Smart. But the brightest stars burn fastest.