Stephanie Cole, Siobhan Redmond and Karl Theobald give us the beautifully observed monologues of Alan Bennett.

These are diamond performances you might wait a life-time to see.

Directed by Sarah Esdaile, each actor creates in the audience’s mind all the characters they describe. They are never alone on the stage. Pathos and humour are there in spades, you cannot cry for laughing, though you should cry really.

Siobhan Redmond’s Lady of Letters, single, middle-aged Irene Ruddock, is a truly dreadful person, so keen to put pen to paper for the public good, so judgemental of others, noting with a lifted eyebrow that her neighbours eat their meals “without a cloth”. They put milk bottles on the table.

Yet here she is also so very endearing. Bennett’s mixture of the tragic and the trivial is irresistibly funny. As Irene Ruddock says when we meet her just after a funeral: “The thing about death is that it involves a lot of correspondence.”

Immaculately dressed with her ironed cardigan, with the pen that has been her constant companion and on her Basildon Bond notepaper, she writes to the chemist about her wrong pills, to a funeral director about his men seen smoking at the back of a crematorium, even to the Queen about dog mess outside Buckingham Palace. She relishes the replies. Even when she thinks the response is a waste of public resources, she will write back to say so.

Her downfall comes when she writes abusive letters about neighbours she thinks are neglecting their child. She goes too far and ends up in prison. But that is her redemption. With her usual gusto, she takes up education courses and the other prisoners enjoy teaching her how to swear. She is no longer just an observer of life. Redmond gives us Irene’s vulnerability and ultimately her delight.

Karl Theobald’s Graham in A Chip in the Sugar is a perfect, camp caricature of Bennett’s mother and son. Part of Bennett’s genius is his language. Graham doesn’t just get his mother upright after a fall. He “restores her to the perpendicular”.

Theobald paints such a perfect picture of the other characters that you see his mother and her old flame, now a traveller in menswear.

We go with them on their outings with Mr Turnbull’s rather common tastes. Graham, and mother usually go out for tea, but Mr Turnbull takes them to gaudy café for a coffee where Graham sees a chip lying in the sugar.

The actor captures it all, the elation of Graham’s mother at the renewed acquaintance as well as his own dismay. The interloper’s fraudulence revealed at the end, comes as no surprise, bursting the bubble but restoring Graham’s version of normality.

Stephanie Cole as Doris in The Cracker Under the Settee is too funny to be sad because her Doris has so much spirit, we love her but we can’t feel sorry for her and she wouldn’t want us to. She is on trial she says. She has to prove she is capable of living in her own home. She has been told the Eubank is now out of bounds, her dusting days are over.

But she still has her standards. There is a morality in hygiene. The cream cracker discovered under the settee is evidence that the home help, is as she says a “home hindrance”.

Trapped on the floor, Stephanie Cole’s performance is as animated as if she is running around the stage.

These three, compelling pictures of the human condition are written with loving precision, observed with irresistible humour and portrayed in unforgettable performances. Each one is a flawless, meticulous masterclass in the actor’s art.