With her children evacuated and her husband at the front, Tory Pace is grudgingly sharing the family home with her irascible mother, working at the local gelatin factory - to help the war effort - and generally doing just about as well as could be expected in difficult times. Her quiet life is thrown into turmoil, however, when her prisoner-of-war husband, Donald, makes an outrageous demand for sexual gratification: He wants a dirty letter!
Towards the end of the Second World War a British artist called Kenneth Brill is arrested for painting near the village of Heathrow. Under interrogation a picture emerges as Brill tells the story of his life. Vanishing sees the world through the eyes of one of the forgotten geniuses of British Art, a man whose artistic vision is so piercing he has trouble seeing what is right in front of him.