In a youth-obsessed culture, John Mortimer is a testament to the virtues of age. And like his autobiographical The Summer of a Dormouse, his latest play borrows its title from Byron and deals with the penalties and pleasures of growing old. It's not going to knock Ibsen off his perch, but it's funny, discursive and filled with delight at the oddity of the human animal.
In his most famous stage work Mortimer took a ruefully affectionate voyage around his father. Here the ageing hero, Harry Pottinger, looks back over his own unspent life. He chats to his boyhood self, brought up in a chilly seaside town as the son of a doubting vicar. More crucially, he looks with regret at the grown-up Harry, who settles for life as a local journalist and succumbs to a sedate marriage, sacrificing the chance of adventure with the flamboyantly flirty Mavis with whom he once enjoyed graveyard sex. The time-defying Mortimer's optimistic message, though, is that it's never too late to change.
The main charge against Harry is that he glides perfunctorily over the social background: the second world war, for instance, comes and goes in the blink of an eye, with just a quick burst of Vera Lynn for period colour. But Mortimer skilfully solves the problem of how to keep us interested in a dull dog who manages to miss life's bus by surrounding him with robust eccentrics: the agnostic vicar who delivers God-free sermons; the seaside editor who models himself on Hollywood prototypes; and the fugitive Mavis, who ends up reporting on revolutions from bullet-riddled balconies.
The play takes several detours, but has a clearly visible destination: the Byronic idea that the most important thing is "to feel that we exist". And the presence of Richard Johnson as the reminiscing hero also lends the text extra depth: once a romantic lead, Johnson has latterly become a fine Chekhovian actor, and here looks back at his character's unfulfilled life with a richly ironic exasperation. Alan Cox exudes buttoned-up decency as his younger self, and Sam Harding is all chipper ebullience in his early boyhood years.
Christopher Morahan's spruce production and Deirdre Clancy's projected images effectively conjure up East Anglia's picturesque bleakness. The play's main appeal, however, lies in its suggestion that age is no barrier to self-renewal. The only problem with that is that, when you can't put your own socks on, it becomes harder to walk out of the front door.
· Until December 8. Box office: 01243 781312.
