John Buchan would probably be appalled at the way his classic The 39 Steps has been lampooned in the adaption by Patrick Barlow at the Criterion Theatre, but it is all good knockabout fun.

The gripping story of how innocent murder suspect Richard Hannay leaves a dead body in his flat so that he can track down a dangerous spy ring is transformed from thriller to delightful slapstick comedy.

What director Maria Aitken's version lacks in suspense it compensates for in humour aplenty, with a cast of four taking on all the many roles. This involves them in sometimes indulging in complete silliness by swopping coats and positions to play two parts at once!

One notable exception is Charles Edwards as the hero Hannay, around whom the plot - considerably watered down - still revolves. Edwards hams it up, but nevertheless shows the same swagger and stiff upper lipped Englishness that Robert Donat, Kenneth More and, to a lesser extent, Robert Powell portrayed in the three film versions.

Rachel Pickup plays the German spy Annabella Schmitt, the blonde, Pamela, who Hannay accosts and later gets handcuffed to, and a Scottish farmer's wife with varying degrees of success. Fortunately, she excels as Pamela and convincingly makes the change from hostile disbeliever to smitten lover.

Rupert Degas and Simon Gregor cleverly fill all the supporting roles between them and Degas has the best line in the show. When he learns that a hymn book in Hannay's coat has prevented a bullet killing him, Degas acknowleges: "Some of these hymns are terribly hard to get through."

It may be almost unrecognisable from the Alfred Hitchcock version in 1935, which itself took some liberties with Buchan's original story, but this enjoyable romp moved at a fast pace while providing plenty of laughs along the way.

  • Criterion Theatre, West End. Booking until September 2007.