They squabble, they bicker and then they squabble some more.
It is a positive joy to watch the two old Jews in The Sunshine Boys arguing. If they cannot do it right, then nobody can. They elevate disagreement to an art form, employing a near-Talmudic logic to score even the most minor point from each other.
They are cantankerous, grumpy, stubborn, spiteful, self-pitying, nit-picking, nasty and vindictive. And those are just their good points.
Neil Simon's classic bitter-sweet comedy sees the pair of them, Al Lewis and Willy Clark - an iconic Vaudeville comedy double act for 43 years - thrown together after more than a decade apart. They are being well paid to do a one-off performance. But they hate each other with a passion. They do not speak, they cannot bear to be in the same room, and now they find themselves rehearsing an old routine together for a CBS television special.
We first see Robert Pickavance, as Willy, shuffling around his dingy Manhattan hotel room in his pyjamas, an unshaven shadow of his former self. He has barely worked since his partner Al called time on their act. Al who poked him in the chest -with the "the sharpest finger in showbiz" - spat in his face, and committed numerous other crimes against him.
David Fielder plays Al, who became a stockbroker after his showbiz career, then retired to live with his daughter in New Jersey.
The humour derives from the sharp dialogue between them, the constant sparring, and the determination to disagree on anything and everything, from the name of a theatre manager from way back to whether the lines in their routines can ever change. For 43 years Willy said "Come in" and now he wants to freshen up the act with "Enter".
But beneath it all, there is a grudging mutual admiration, and quite possibly, despite appearances, an affection of sorts as they near the end of life's journey.
Willy's nephew and agent Ben (Dominic Gately) engineers the first meeting. Willy brings Al a cup of tea, but places it on the table because he will not hand it to him. That sets the tone.
The action is limited to Willy's shabby room and the CBS studio, when the ageing duo suddenly lose a few decades as they reprise their "legendary" doctor sketch. That is when you realise how funny they are as themselves.
If you have seen the 1975 film version you will find this production - directed by Joyce Branagh - enjoyable but unremarkable. Fielder and Pickavance are competent but lack a little in inspiration. I feel mean saying that - after all, it is not their fault they are not George Burns and Walter Matthau who were very deliberately cast in the movie. However, their attempts at Jewish mannerisms do help to bring an authentic flavour to the proceedings - it is just that I could have done with more of it.
Having said that, it was a pity to see so few people in the audience - the evening deserved better than a half-empty house.
I genuinely felt for Fielder at the end of the show when he urged those who had enjoyed it to tell their friends. (Until October 23. Tel: 0161 624 2829)