A foghorn can be heard in the distance and a cloud of fog wafts across the impeccably constructed set of designer Quentin Mitchell and into the small auditorium of Theatre 3. It heralds the unfolding mystery of Canberra Rep's production of Agatha Christie's Witness For The Prosecution. Britain's queen of crime fiction departs from the sleuthing of quaint Miss Marple and the idiosyncratic Hercule Poirot to enter the formal world of the law and the courtroom. It is a male domain in which women cannot be trusted and foreigners are to be regarded with suspicion. It is 1952 and misogyny prevails. Postwar Britain clings tenaciously to the past as it confronts a changing order.

In Arne Neeme's carefully observed production, Sir Wilfrid Robarts QC (Pat Gallagher), solicitor Mr Mayhew (Jerry Hearn) and prosecutor Mr Myers QC (Peter Holland) exude the pomposity and self-assurance of their status. It is the women who are relegated to subservient roles in the case of Sir Wilfrid's secretary Greta (a delightfully coquettish performance by Morgan Heathwilliams) and murdered Emily French's housekeeper Janet Mackenzie, played with feisty conviction by Alice Ferguson. Emma Wood as Romaine, the foreign wife of defendant Leonard Vole (Cole Hilder), imbues her character with mystery. Suspicion is aroused and Sir Wilfrid's closing comment at the end of the first act takes on an ominous significance: "Never trust a woman."

Director Neeme clearly understands Christie's intent in writing the original short story. The consequences of the war are still apparent. Women have once again been relegated to pre-war roles and, in 1952, the king has died and a young queen has ascended to the throne. The arrest of young Leonard Vole and his subsequent trial in an intriguing and formal, traditional courtroom process serves as Christie's astute commentary on conservative values and traditional expectations. Through it all, she weaves her intricate web of clues and twists and turns to bewilder and intrigue. The audience becomes the jury, engrossed in the argument, assailed by clues and eventually most cunningly manipulated by Christie's ingenious surprise ending.

Courtroom dramas present unique challenges for a cast. The formality can evoke a ponderous performance. Rep's production took halting steps during the first scene, relieved by the energy of Heathwilliams. Neeme has assembled a competent and experienced cast of Rep stalwarts in Gallagher, Hearn, Wood and Holland and there are confident performances by Ferguson and a brief cameo by Lauren Atkin but suspense and tension are hampered by slow and deliberate pacing.

Christie's art is to keep you guessing and then with surprising sleight dispel all theories in a final, unexpected revelation. The closing scene achieves this with gasping effect, but this production of Witness For The Prosecution still needs to thrill as well as simply entertain.