First nights are scary enough without a dysfunctional prop in the opening scene. My sympathies, then, to Sally Oliver and Terence Booth, who had to hack away at an uncooperative champagne bottle before their characters' scripted birthday celebrations could begin. The play is similarly stubborn. David Auburn's Proof, which won a Pulitzer prize in 2001 before debuting in London with Gwyneth Paltrow a year later, is likewise all bubbles and no popping corks.
Its heroine is Catherine, daughter of a recently deceased Chicago maths genius. The genius, in accordance with dramatic convention, was mentally ill, and Catherine gave up her own maths studies to care for him. Now she claims to have written a pioneering proof discovered among his papers. But her sister Claire doesn't believe her, and thinks she's going down the same path as daddy.
This, then, is an old-fashioned play lent sparkle by Paltrow's stardust and its flirtation with Big Themes. "Is Truth," as the poster asks, "more important than Love?" That love involves the dad's former student, Hal, who, after one night with Catherine, is expected to trust her when she professes to have revolutionised mathematics. But theirs is too slight a relationship to shoulder a debate on love and truth. Nor is the play interested in maths. Catherine's proof, and her father's earlier achievements, are never explained.
Proof is less drama about numbers, more drama by numbers - an elegantly turned domestic confection that, in John Harrison's production for Birmingham Stage Company, never rises above the mildest of theatrical temperatures. Newcomer Oliver is engaging as Catherine, without suggesting there is more at stake than the fickle fancies of a talented but petulant youngster. Passion is lacking. The cork stays firmly in the bottle.
· Until March 17. Box office: 0870 0601742.
