Mike Davies plays nurses with Emma Thompson...?
A nanny who appears from nowhere and uses her magical powers to transform the lives of a bunch of children? Been there, done that. Except, this isn't Mary Poppins. No, this is Nanny McPhee and she's an entirely different creature altogether.
Though little known these days, during the early 60s award-winning mystery writer Mary Christianna Lewis produced a series of books under the pen name of Christianna Brand, drawing on the tales of one Nurse Matilda, a warty faced, bulbous-nosed nanny who tames a large family of extremely unruly children using magic to teach them lessons. As they learn the lessons so her appearance seems to change.
The stories passed down through generations of her family, Brand first introduced the character in her anthology Naughty Children, illustrated by her famous cousin Edward Ardizzone, before developing the adventures further in her three children's novels, Nurse Matilda, Nurse Matilda Goes To Town and Nurse Matilda Goes To Hospital.
The character might have remained forgotten had Emma Thompson not rediscovered her old childhood copies on the bookshelf some eight years ago.
"They weren't my main fare when I was growing up," says the Oscar winning actress, "but I did remember that I had loved reading them and the illustrations and that they were very dry and witty and dark, but also very sweet. It started me thinking they would make a good film."
She's not wrong. Re-teamed with producer Lindsey Doran with whom she made Sense & Sensibility and with Waking Ned director Kirk Jones at the helm, an arduous process of tackling the first book's virtually plotless cocktail of farce, spookiness, drama and physical comedy has finally borne marvellous family entertainment fruit in Nanny McPhee.
So, what happened to Nurse Matilda? With Roald Dahl's Matilda to contend with not to mention rumours about some Emma Thompson nurse movie, one of the first decisions was to change the character's name.
Since, during the period the books were set, nurse was synonymous with nanny, that became a given and it was Thompson's own mother, Phyllida Law who came up with McPhee.
She also intones the words "the person you need is Nanny McPhee" that the beleaguered father, played by Colin Firth, hears at the start of the film.
It's fitting that Thompson, whose father Eric created the English version of The Magic Roundabout, should eventually find herself writing a children's film. Unsurprisingly, she owns up to it being very much a tribute to dad.
"He never talked down to us when we were children," she recalls.
"He would always read to us in his normal voice. I very much wanted to write something in homage to him because when the Magic Roundabout became a successs he had no copyright over the scripts or the characters.
"The BBC only paid him about a fiver a programme and all the spin off stories about the characters were written by these ladies in lavender, it was terrible to see such an original mind being distorted by these suburban women writing such awful stories!"
Aside from writing the screenplay, it was always a given that Thompson would also play Nanny McPhee. She remains totally faithful to Brand's physical description and Ardizzone's illustrations, complete with large ears, two hairy warts, thick eyebrows that join in the middle, and what the author described as 'a nose like two potatoes and a tombstone tooth'.
She's not the first actress to get a kick out of playing ugly, but, as she says, the physical appearance isn't the point. It's all a matter of perception.
As the children's behaviour improves, so do McPhee's disfigurements disappear. Or do they?
"I hope it's clear that Nanny McPhee is the same when she arrives as when she leaves," stresses Thompson.
"The message is that it's others' perceptions of her that is different. Before we started we were worried that we might be in danger of reinforcing the idea that you have to look beautiful, but its clear that's not what children get from it.
"They understand that it's about perception. We don't actually know what she looks like because we only see her the way the children do. Lindsey found this Norwegian proverb that says 'that which is calm is always beautiful', and that's what the metaphor is."
Given the film is about a family of mischievous children who learn lessons about how to behave, one wonders whether perhaps Thompson drew on her own childhood and nanny experiences.
"I was quite good as a child," she smiles with mock smugness.
"Though I did draw all over the toilet wall and was made to rub it all off. But I vividly remember when I was seven having this particularly large evil Polish nanny called Paula who ate all my Meltis Newberry Fruits when I was in hospital after my tonsillectomy. I didn't even like them but I ran away from home in the middle of the night with my sister dressed up in our balaclavas.
"We took a bagful of McVita biscuits and went round the corner to sit behind a tree next to our nursery school. Then about 5am we went back and rang the bell. My parents were away and she opened the door and I said 'we ran away but we're back now.' She glared balefully at us, but nothing more was ever said about it!"
With two more books available for adaptation and Thompson's own idea of setting a story during the second world war with McPhee as a warden turning up to look after evacuees a sequel seems certain. But while copyright would make it impossible to do, what does Thompson think might happen if Nanny McPhee and Mary Poppins ever got together?
"I think Mary Poppins would be very defensive," she laughs.
"Nanny McPhee is not a person to rush round the house thinking she's perfect. Mary Poppins is frisky and everything Nanny McPhee is not and I think that strange calmness would cause a nervous reaction!"