Patrick Barlow's The 39 Steps reflects a curious history of adaptation. John Buchan's 1915 spy novel The Thirty Nine Steps changed somewhat when Alfred Hitchcock filmed it in 1935 and it is Hitchcock's version rather than Buchan's that Barlow adapted for the stage in 2005.

Buchan's original serious and slightly fey story does not stand a chance. What results is broad and exhilaratingly comic, especially if you know your Hitchcock.

Hero Richard Hannay (Patrick Galen-Mules) is short of adventure in his London flat until a chance visit to the theatre leads to a dead body draped over his furniture. He flees to Scotland, knowing he will be accused of the murder. There he encounters evil and espionage and more escaping from police and people who may not be what they say they are. He spends much time handcuffed to Pamela (Steph Roberts), a young woman who reluctantly becomes involved with his flight, before a return to the theatre resolves the chaotic plot.

The whole thing is done by four actors with a mostly clever set and minimal resources. Galen-Mules remains in the one role as Hannay throughout. Steph Roberts plays the mysterious Annabella, the cool heroine Pamela, and Margaret, the Scottish woman who helps Hannay when he is on the run. Pretty well everyone else is played by the Clowns (Helen McFarlane and Nelson Blattman) regardless of gender and the need for rapid changes of costume.

Hannay is given the full magnificent stiff upper lip treatment by Galen-Mules who manages to stay just clear of being too over the top. Roberts juggles her three roles deftly, from Germanic Annabella to tartan draped Margaret who helps Hannay because she rather fancies him despite (or because of) the presence of her much older repressive bible-bashing husband (McFarlane). I'm not sure why Pamela is not the usual Hitchcock blonde but Roberts gives her a good streak of common sense as she copes with being caught up with Hannay's flight.

Blattman and McFarlane make multiple roles look easy as they transform, often in front of the audience. Together they lurk in corners and in shadows and are highly adept at double acts like the sleazy underwear salesmen on the train to Scotland. A more assured style for the pivotal role of music hall turn Mr Memory is needed but Blattman certainly has a good line in the devious cameos required by the plot. McFarlane grabs the attention frequently with funny and clear characters, especially the evil mastermind at the centre of the mystery.

If you are looking for an evening of enjoyable theatrical chaos that is not too demanding then The 39 Steps is the go.