It is the tutor who tells the young Gustav that he must try to be more like a coconut - that he needs a hard shell to protect the softness inside. This is what his native Switzerland has perfected - a shell to protect its neutrality, to keep its people safe. But his beloved friend, Anton, doesn't want to be safe - a gifted pianist, he longs to make his mark on the world outside. On holiday one summer in Davos, the boys stumble across a remote building. Long ago, it was a TB sanitorium; now it is wrecked and derelict. Here, they play a game of life and death, deciding which of their imaginary patients must burn. It becomes their secret. 'The Gustav Sonata' begins in the 1930s, under the shadow of the Second World War, and follows the boys into maturity, and middle age, where their friendship is tested as never before.