As Her Majesty the Queen has lately turned to playing herself in British film and entertainment ("Good evening, Mr Bond"), Nichola McAuliffe has had to get in quick with a royal impersonation before the job opportunity is withdrawn altogether.

Not only that, she's written the royal play herself, and the funniest queenly lines since Alan Bennett's for Prunella Scales in A Question of Attribution. Prompted by those surprise jubilee descents on suburbia, she places her doughty monarch -- a sedate vision in shocking turquoise with hooded eyes and bursting vowels - in a retirement bungalow in Penge, home of an 89 year-old jeweller.

Maurice and Helena -- a lovely pairing of oak-like Julian Glover and flitting little jenny wren, Sheila Reid -- had shares with Bradford & Bingley and savings in Northern Rock, which explains why they've downsized from Barnes.

And there's been another woman in their 66 years of marriage: a young princess on the eve of her coronation whom Maurice visited in Buckingham Palace in his role as caretaker to the crown jewels; she promised to find him again should she achieve sixty years on the throne.

She's only just in time, for Maurice is fading fast and has just hired a live-in carer, Katy from Tufnell Park, to share the burden with Helena. Director Hannah Eidinow sets up the reunion with a delicious sleight of hand, allowing Glover a twenty-minute speech which freezes the action in a memorial glow of touching reminiscence.

There's an added piquancy with Maurice and Helena's son stranded on the other side of the world on dad's birthday ("Can I call you back; I've got someone with me"), and the final few moments are both deeply moving and surprising. The mostly elderly audience were on their feet, and not just because they needed a corporate dash to the loo after a bewitching ninety minutes.