The 39 Steps is a classic adventure novel by John Buchan, and an early but influential thriller by Alfred Hitchcock, and now a witty stage play paying irreverent homage to both.
Richard Hannay is the dashing, pencil-moustached hero, unwittingly caught up in an espionage adventure when he tries to protect a beautiful, mysterious foreign agent from unknown assailants.
With her dying words, she tells him of a ploy to smuggle crucial war secrets out of Britain, and sends him to a lonely address in the Scottish Highlands in a bid to foil the dastardly plot.
Faster than you can say, “There are 20 million women on this island and I get to be chained to you,” Hannay has ridden the roof of a moving train, swung from a railway bridge and evaded squadrons of police pursuing him across the Highlands, much of this while handcuffed to the rather hapless heroine.
Most impressively, all of these antics are performed by a mere cast of four, with little more in props than could fit in a large tea chest.
The point of it is not really to tell the story of The 39 Steps, but to demonstrate how much fun they can have mimicking Hitchcock’s film on stage.
Classic action scenes are lovingly recreated, and the low-fi comic effects regularly elicit rounds of applause.
Eventually though, the incessant invention and theatrical in-jokes get predictable, and the play underneath it all, by Patrick Barlow, is rather flat.
The concept is little more than a sketch, and it should be half an hour shorter and played without interval.
But the cast works hard to keep us laughing, particularly Dan Starkey, a man with an extraordinary ability to turn himself into a cartoon character.
And only a curmudgeon (or a critic) could complain that a play has too many jokes.

Reviewed for the Irish Independent at the Olympia, Dublin, on May 25.