Dining alone in an elegant Parisian brasserie, accountant Daniel Mercier can hardly believe his eyes when President François Mitterrand sits down to eat at the table next to him. Once the presidential party has gone, Daniel discovers that Mitterrand's black felt hat has been left behind. After a few moments' soul-searching, Daniel decides to keep the hat as a souvenir of an extraordinary evening. It's a perfect fit, and as he leaves the restaurant Daniel begins to feel somehow different. Has Daniel unwittingly discovered the secret of supreme power? For two years the iconic item of headgear plays with the lives of the men and women who wear it, bringing them success that had previously eluded them.