This must surely be one of Ayckbourn’s best plays, a pretty large claim when one considers his enormous output, none of it less than competently entertaining, and the best of it – like this one – work of intense human interest and real literary merit.

But it’s not a piece that’s easy to do well: for a start, it’s supposedly a comedy, and indeed it’s full of laughs, but it shows us in awful detail a woman, trapped in a loveless marriage, descending into madness before our eyes. Getting the right balance between comedy and tragedy is not an easy task for director and actors – the effect to aim for is to make the audience laugh, then to make them feel immediately guilty for laughing. The piece has other challenges: for example, the audience needs to quickly recognise what the hallucination scenes are all about; and the real-life characters are mostly either inadequate or deeply unsympathetic, or both. Above all, it depends more than most Ayckbourn plays on a tour de force performance by the actor playing the central character, Susan.

So how did they do? Pretty well, I thought. The first hurdle, to make us realise what’s really going on between Susan and her imaginary family, was easily cleared with the help of clever set design, good lighting and sound, and excellent performances from Andrew Lee, Paul Morton, Alex Brace and Jenny Macchia as Susan’s dream family. It was a good idea to put the imaginary garden at the front of the stage – other productions I’ve seen have had it at the back – because it helped to give the right effect of hyperreality. The warm lighting, in stark contrast to the rather cold effect of the real garden, was a key element here, though personally I’d have made it even brighter than it was. The birdsong helped too, but it seemed to be omitted in some of the later scenes, which was a pity. The key element in the success of these scenes – apart of course from Ayckbourn’s delightfully tongue-in-cheek parody of romantic fiction – was the ever-so-slightly over the top acting by the family. Well done to them all.

Bill Windsor, the ineffective doctor, is a gem of a part, strongly reminiscent of Tom, the bumbling vet in The Norman Conquests. Andrew Lee got pretty much all the laughs he was entitled to out of it, though he might have had a few more if he’d put a bigger filling of medical gravitas between the bread and butter of medical inadequacy. Part of the comic effect should come from the contrast between the surface appearance of professional dignity and the revelations of actual incompetence. It was nevertheless an excellent comic performance, and the naive revelation of his wife’s affair with his colleague was delightfully done.

Gerald, Susan’s dreadful husband, is quite hard to play. I say this with some feeling, have played the role myself. The difficulty lies in making a rather boring and totally unsympathetic character comic, and I’m pretty sure I failed. I hope Peter Dukes won’t think I’m damning him with faint praise when I say he made a better fist of the role than I did. I thought his reactions to his awful sister Muriel were subtly and comically done, and he never once lost his straight face at the sheer awfulness of the character he played.

Muriel, Gerald’s even more awful sister, was played with her customary comic flair by Jackie Lawn. A lovely performance, just what I’ve come to expect of her.

Rick, Gerald’s and Susan’s only son, is a relatively small part, but it was played with understated skill by Jordan Blaxill. This young man is a natural actor: he has that certain stillness and the stage presence that so often goes with it. Highest praise of all, he really inhabited the part, making us see the point of view and even sympathise with the priggish, brutally frank and self-centred person he was playing.

But the biggest acting challenge of all lies in the part of Susan, played by Maggie Box. She certainly rose reliably to the challenge, and the overall success of this production owed a lot to her.

The one scene that didn’t work in this otherwise highly competent production was the storm scene near the end. It had a curiously hesitant and under-rehearsed feel to it, and it lacked the technical sure-footedness of the rest of the production: I was never for a moment convinced that it was pouring with rain. But that one failure was counterbalanced by much that was very accomplished: the highlights for me, apart from the meeting with Rick which I’ve already mentioned, were the hallucination scenes, most particularly when they twisted into menace. The final scene in particular was superbly done. So congratulations to all concerned for giving us such an excellent account of a modern masterpiece.