IF you know Caitlin McNamara at all, you will know she was the wife of that dissolute Welsh genius Dylan Thomas.

She suffered for his art, in the shadow of his poetry, for 20 years together and 40 years beyond his drunken death in New York.

She stands wrapped in her coat and her thoughts, looking out to sea at Laugharne, her final resting place alongside Dylan on the Welsh coast. "I was a dancer," she says, as she steps from darkness into light, and, in Mike Kenny's biographical play, it is her chance to dance.

As she walks, however, the gantry suddenly shunts forward, crushing a sand castle in a symbol of the troubled path that lies ahead. Designer Siobhan Ferrie's wooden structures around her are worn by the tides of time too.

Removing her shoes to bathe her feet on the Laugharne sands, this Caitlin is in the reflective years of her life. Played by Kenny's wife, Barbara Marten, she retains the slim features and grace of body and face of a dancer, and the vestiges of a former suppleness remain.

It would have been tidy and neat if this study of the husband-and-wife relationship had been written by Kenny for his wife, but instead it was commissioned by the Sherman Theatre, Cardiff, to mark the 50th anniversary of Thomas's death last year. However, Marten was drawn to the role, which now forms her return to the stage, after six years of radio and television commitments.

What a play to choose, a one-woman show, except that like Christine Jeffs's literary biopic of Sylvia Plath, Sylvia, this is no one-woman show.

As with Ted Hughes, Dylan Thomas is omnipresent, even when he is not there, and in this play Dylan is only there in spirit and spirits. Just as he was never at home in the evenings; just as he never brought Caitlin to full satisfaction; just as Dylan's poetry is never heard but is somehow all around (even in printed form in the foyer).

Caitlin talks of "the whole of our marriage" and then repeats the phrase as if to suggest "the hole of our marriage".

Unlike the needy Sylvia Plath who continued to write while cherishing the role of domestic goddess, Caitlin curtailed her own artistic endeavours to give her all to her errant Dylan, and that frustration at a stymied life and at his philandering spills over in bitter bursts of coarse language. There is fury and fire, dismissing his love letters as lies, and yet tenderness and an undying love too.

Marten's ravaged and ravishing performance, Damian Cruden's immaculate direction and Christopher Madin's piano pieces make this a wonderful start to the Studio spring season.

Box office: 01904 623568.

Updated: 12:06 Wednesday, February 18, 2004