Surviving Spike, Theatre Royal, Windsor

Given his past troubles, Michael Barrymore may not have had to dig too deep to discover the anguish needed for his portrayal of Spike Milligan. It might even have been enough for him to summon the painful memory of his dramatically curtailed West End stand-up run of 2003. I witnessed that unfortunate episode and believed then that the only way back for Barrymore would be through a lucky break getting him back on TV.

It's debatable whether Celebrity Big Brother was such a break, but neither I nor the 55-year-old comedian, whose last stage acting role before Scrooge the Musical, in 2006, was his audition for drama school aged 19, could have thought that artistic salvation would come through theatre.

Certainly, Barrymore's turn in Surviving Spike looks set to be a happier event than his one-man show was. Reminders of Barrymore's past are never far away, as the visit of the father of Stuart Lubbock (the young man found dead in Barrymore's swimming pool in 2001) to the show the previous night underlined. However, while his name and reputation loom large over this production, Surviving Spike is the story of Norma Farnes, Spike Milligan's long-suffering but devoted right-hand woman for 36 years, so the plaudits and spotlight linger longest over his co-star Jill Halfpenny.

Known for roles in Waterloo Road and EastEnders, and for winning Strictly Come Dancing, Halfpenny's breezy portrayal of Farnes, a bright-as-a-button Northerner-with-nous, lends added zip to what is already a tightly written play. In her narration and dialogue, Halfpenny successfully evokes the tenacity that Farnes must have had to survive Milligan's ability randomly to evoke hilarity and despair. And the relationship between the two intrigues, as a study of creator and administrator.

The chemistry between the two, though slow-burning, is evident. The pace is initially skewed by the "narrative-action-narrative-action" rhythm, but also by Barrymore avoiding playing up to the zany public image of Milligan.

When Spike's third and last wife says, "I love the energy of him, he's like electricity", you think that, accordingly, Barrymore's portrayal could up the voltage a bit. And Barrymore doesn't fully explore the depth of Milligan's despair, nor the giddy playfulness at the other end of his bipolar scale.

To 16 February (01753-853 888)