Watch (2002)

A seasoned call girl is offered a way out of the business if she uncovers a blackmail ring in a house of prostitution. An alcoholic ex-school teacher takes a job watching security cameras in the same house. There, he befriends a 13 year old boy left behind years before by his mother. When a blackmail victim murders one of the girls and the bosses move in to violently clean house, the teacher and the call girl risk their lives to save the life of the boy.