There is a house occupied by two sisters who 'wholeheartedly' love each other more than anyone else in the world, their servant maids, and a vicious but admired madam.

The one and only amusement of the two sisters is to put on an act in which "the maids kill madam" when madam goes out.

They are putting out this act as they always do after madam goes out when they receive a phone call that madam's boyfriend, monsieur, whom they falsely imprisoned to give pain to madam, will be released from prison.

At the very tip of their inescapable destiny, they decide to murder madam by poisoning her with tea...