Following the spate of Round the Horne “live recording” radio shows, The Fitzrovia Radio Hour seems a little "yesterday" in giving a theatrical dimension to funny voices and sound effects performed in a sort of stealthy conspiracy with the audience while the red light shines.

The show follows the separately ticketed Barbershopera: Apocalypse? No! in the smaller of the Trafalgar Studios (though you can double up if you want to) and, running at eighty minutes, rather begins to outstay its welcome, which was only lukewarm to start with.

The brilliant thing to be done here would be an inner play among the protagonists while they perform the "outer show" and, while there are hints this might be about to happen, it never does.

Also, the three stories performed by old-fashioned BBC rep actors speaking like John Mills and Margaret Lockwood are divided by advertisements for medical pick-me-ups, a feature of American radio, not British.

As with Barbershopera, there is a faint post-Modernist whiff of the Goons, The Navy Lark, Dick Barton and other long lost radio causes, but once you’ve created bats flying by flapping rubber gloves, or bones crunching by rummaging in a bowl of cornflakes, or a blow to the head by thumping a cabbage with a mallet, you’ve nowhere very much to move on to.

The five actors perform dextrously enough, three boys (Tom Mallaburn, Phil Mulryne and Alex Ratcliffe) in black tie and dinner suits (plus assorted headgear) and the girls (Natalie Ball and Alix Dunmore) in period skirts and hairstyles.

And the three stories are cleverly spliced, each told in two parts: a dastardly body swap in the British Museum, involving an undead ancient queen; an Indian spy adventure with hidden treasure in the mountains; and a Yorkshire morality tale of a lathe worker in Leeds who switches jobs, moves up in the world to Roundhay and pays dearly for rebuffing the boss’s wife.