The Unholy Four, also known as Chuck Mool, is a 1970 Italian Spaghetti Western. The film represents the directorial debut of Enzo Barboni, who was, until then, a respected cinematographer. He replaced Ferdinando Baldi, who was fired by the producer Manolo Bolognini because of his insistence in wanting to engage the actress Annabella Incontrera in the role of Sheila.