The year 1914. The Lasarte racetrack announces a race with a never-before-seen prize for the winning horse. Eight of the best horses and mares in the world have registered. Fans and heavy betters from all the continents gather to participate in the great event: the Half Million Grand Prize.

Madrid, Spain, 1936. The young Miguel Gila lives happily with his grandparents in a humble attic; but the outbreak of the Civil War forces him to go to fight.