Here we have another prime example of the psycho-biddy genre. Bette Davis, no longer shackled to Joan Crawford, is given a whole film to chew.
We see the Nanny (Davis) as she readies herself for the day. She seems hardworking, kind, why she even takes time out to feed some ducks in the park.
Today is a special day though, as her employer's son Joey (William Dix) is finally coming home from school. Joey is an unusual boy, in that he seems to take special delight in shocking, scarring, and generally being a utter ass to any middle-aged woman who dares intrude on his space, as evidenced by his pretending to hang himself at the institute. Yes, institute, as it seems Joey has been locked up despite what he parents claim.
He holds Nanny in special contempt. He refuses to eat any food she's made, won't sleep in his old room (wanting one with a fire escape and window access), and generally insults her at every chance. Nanny is patient though, as young Joey is obviously still acting out after the death of his younger sister Susy (Anghared Aubrey) two years ago.
The mother, Virginia (Wendy Craig) is a nervous wreck. It seems Nanny was her nanny when she was a child and she insisted the older woman stay on, although frankly she seems to spend more time taking care of Virginia than Joey. The father, Bill (James Villiers) is your typical office drone and doesn't seem involved with his family that much. Which is a problem, as he has to leave on a business trip after his wife is bed ridden, leaving Joey entirely in Nanny's care.
A few twists, but overall fantastic. Davis is utterly perfectly as the titular character. She's outwardly warm, but one glance at her eyes reveals what's she's thinking. The tension grows and grows until it finally explodes.