Lord of the Rings: The Return of the King - The Witch King's Helmet
After the Witch King's dragon throws Theoden and his horse, Eowyn comes to rescue him. There is a shot of the Witch King coming on his dragon saying "Do not come between the Nazgul and his prey". The bottom of the Witch King's helmet is together. Later, when the Witch King's fighting Eowyn, the bottom (the chin area) of his helmet is spaced apart.