Cause Celebre may have all the twists and turns of a gritty courtroom drama but it is far from your average whodunit.

Anne-Marie Duff’s Alma Rattenbury – up in the dock for confessing to the murder of her wealthy, decrepit husband ‘Rats’ – is wonderfully wayward yet fragile, endearing yet self-seeking, however, as the play goes on our attention is less fixed on her motive for the crime and more in the context in which it occurred.

Renowned playwright Terence Rattigan set the events as they occurred in real-life – in a 1930s upper-class Bournemouth neighbourhood.

In this revival to celebrate his centenery, Alma, a mother-of-two who enjoys nothing more than a strong gin while giddy-footedly prancing around the gramophone, goes out of her way to employ strapping 17-year-old George Wood as an odd jobs boy.

It doesn’t take long for the pair to jump into bed with each other and then, out of nowhere it seems, Alma bumps off Rats.

But things are not quite as simple as that and the menagerie of lawyers brought in to try and work out what the heck actually happened make for some thrilling scenes.

Rattigan’s fixation with society’s role in all of this - its prejudices and limitations on the role of women – manifests itself in a sub plot led by Niamh Cusack’s Edith Davenport.

Edith is made forewoman of the jury deciding Alma’s fate, at the same time as going through a divorce from her adulterous husband.

She despises everything Alma stands for and all the while we are urged to access the mechanics of the two women – both very much judged by the society they live in.

The performances are spot on and the message of the play remains clear while never forcing us to take one side or the other.

But while Duff portrays Alma with all the vitality and pathos she deserves, the script never quite explains why she does decide to stick by her na�ve young lover.

Despite that, there is enough in this clever and well-acted play to get you thinking.

Cause Celebre is at the Old Vic until June 11.

See oldvictheatre.com