In an east end warehouse Dick Barton, special agent, defender of the free world, is about to meet his mincer. His arch-enemy, Baron Scarface - brought up by wolves and educated at Eton - has him suspended over three tons of rotating sharpened steel. It looks as if it's going to be a case of diced Dick.

I must admit I had my doubts about this stage version of the 40s radio series. But in fact this evening of daft songs and inspired silliness is a winning formula. Phil Willmott's script, staged with gusto by Stefan Bednarczyk and Ted Craig, walks a very fine line between homage and camp spoof.

The result is something that captures all the patriotic fervour of Hun-hating post-war Britain even as it sends it up rotten. It is both entirely innocent and good clean filth, typified by Barton's throwaway line, "Every time I think of the Princess Elizabeth, my resolve stiffens."

Willmott's master strokes are to plunder the Radio 4 format to give the piece a period feel, to invent a fiendishly complicated plot featuring the evil Baron and the femme fatale Marta Heartburn, and to treat Barton with enormous affection while exploding the myth of the square-jawed, unassailable English hero.

The cast of five work like the devil to keep the gags coming thick and fast, and Andrew C Wadsworth gives a wonderfully tongue-in-cheek performance as the hero. I haven't had such fun in the theatre for weeks.

• Till July 18. Box-office: 0181- 680 4060.