"We were terrified. That's a wee understatement for you." Unless the afterlife really does exist, Andrew Davies will never have to argue his case with Jane Austen or George Eliot. Not so John Binnie. His adaptation of Babycakes, the fourth volume of Armistead Maupin's Tales of the City, has just opened and he and his company, Clyde Unity Theatre, had the pleasure of the author's company for the last four days of rehearsal.

They needn't have worried. Maupin was generous in his praise, valuing the opportunity to see the characters he created 13 years ago through the prism of Binnie's script. Not that the journey has occasioned unclouded joy. On their initial contact, Maupin queried how the hell he was going to adapt such a complicated book. After much friendly chat about Binnie's 10-year history with his company, Maupin granted him the rights, giving him free reign, but proved less than happy upon receiving the script. He argued that Binnie had missed the tone in places. Exit draft one. Binnie persevered, however, and he and director Ian Brown believe their result is genuinely theatrical.

"Babycakes is more of a chamber piece than the first three books. There are only six or seven main characters, but the cast of eight also do a lot of doubling. They all put moustaches on to play a bunch of clones camping in the desert and Louise Brooks wigs to take part in a dyke disco."

As anyone who has read the book knows, it's not all laughs. Indeed, when he first read it, he was reduced to tears. "In many ways it's about mourning and finding a way with getting on with your life after someone dies." The teacher and close friend who gave him the book recently died, lending the project an added poignancy for Binnie, but there are other reasons for setting up a project which has taken more than 10 (happy) months to reach fruition. "I'm in my early thirties, the age of the principal characters, and a lot of it is about having children and thinking about how you make your mark upon the world." Comedy is, after all, a serious business.