This is the Sunday Times Top Ten Bestseller. It was shortlisted for the Costa Novel Award. What is the difference between friendship and love? Gustav grows up in a small town in Switzerland, where the horrors of the Second World War seem a distant echo. But Gustav's father has mysteriously died, and his adored mother Emilie is strangely cold and indifferent to him. Gustav's life is a lonely one until he meets Anton. An intense lifelong friendship develops but Anton fails to understand how deeply and irrevocably his life and Gustav's are entwined until it is almost too late..."This is a perfect novel." (Observer). "The Gustav Sonata is beautifully rendered, and magnificent in its scope. It glows with mastery." (Ian McEwan).