Juliette Binoche plays a well-known French author who goes undercover to research a book on the working conditions of the cleaners (mostly women) on the cross-channel ferries.  

Working with these women, she experiences first-hand not only how appalling are their conditions but the strong bonds they share, the solidarity that exists among them. She makes friends with two of the women but is always aware that she is deceiving them and that one day the truth will out.