A blood-spattered staircase, the glimpse of a corpse's foot: thus we are enticed into the true story of a murder which occurred in Le Mans in 1933. Two sisters (Richardson and May) become maids in the bourgeois household of Mme Danzard (Walters) and her daughter Isabelle (Thursfield). Immaculately groomed, discreet and conscientious, at first they seem ideal servants. But upstairs in the sisters' attic bedroom a heated incestuous relationship is developing. The film, backed by Channel 4, is enveloped by the claustrophobia of the house, where Madame dominates her lumpen daughter and obsessively checks for dust with white gloves. The tensions within unhealthy relationships are convincingly explored, but never quite justify the final eruption of appalling violence.