Inferno.

Sin City contract starlet Hannah Harper stars in this dark tale of a beautiful young government agent who goes deep undercover into the steaming underworld of a man named Price, who runs an exclusive brothel that specializes in the most gorgeous red-headed women available. When she infiltrates the business, she finds herself trapped in a perverted world of dominance and submission, in which she becomes the sexual property of the very man she's been assigned to take down. Compelled into the wild all night orgies, the sizzling lesbian encounters, and the depraved anal, she realizes her own sexual identity, and that she can never go back to the life she once lived before falling into the depths of this raging INFERNO.