Diamantino is a soccer (football) savant-otherwise a dimwit. He is a Portuguese national hero until he fails to make a relatively straight forward penalty goal at an important game. He resigns from the sport, and becomes part of a weird political plot to separate Portugal from the European Union and create a fascist state, of which he is oblivious.
"Admittedly, a film like this may not be to all tastes, but those with a taste for the silly and the strange should get a kick out of it." [Peter Sobczynski at Roger Ebert.]