Progress in Flying Machines, BAC, London

On a wing and a prayer

It's nice, for a change, to get more than expected. As well as a history of those over-optimistic men who stepped from heights wearing homemade wings, Progress in Flying Machines is a meditation on the emotion that, metaphorically, can send us soaring through the clouds. In this show, however, the hopes of lovers crash as dramatically as the flyboys.

With the tales of misguided aviators, the director, Paul King (who created the show along with two of its actors, David Mitchell and Robert Webb), has woven the story of an engineer, on a flight to Budapest, who is accosted by a con artist whose scams grow ever more fantastic. By the time they arrive, he claims he is trying to get to Dar-es-Salaam to lay on the grave of the only girl he ever loved flowers that grew beside a pool where she swam in North Wales. "Those flowers," the other points out, "are plastic." The engineer is particularly vulnerable because he made the same trip with his former lover, and he has left his flat full of possessions, memories, and her voice.

His sorrow is paralleled by that of the wife of one of the inventors. Bedridden, she soars in spirit, while her husband remains earthbound, emotionally as well as physically. Flying, she says, must be much easier than her husband believes: "All you have to do is surrender, give up every part of yourself to the air, and you will be as light as air... My husband tries far too hard. The harder you try, the more difficult it is."

Progress glides gracefully past the sentimental pitfalls of its subject, understatement its keynote. (Alice Lowe, the third member of the cast, even gives an understated portrayal of an anxious monkey.) When the engineer relives his abandonment, when the wife is hurt by her husband's insensitivity, we are not presented with their self-pity but with their bewilderment at the human condition. Progress in Flying Machines is less successful, however, at maintaining a constant tone, combining its reflections with such anecdotes as that of the inventor who, after a painful failure with hydrogen-filled sleeves, notes, "Add hydrogen chaps." Instead of a play that blends serious moments and silly ones, this feels at times like an alternation of theatrical scenes and nightclub turns (Mitchell and Webb are a comedy team). The ending also doesn't feel quite right – it brings the various strands of the play together in a way that is poetic but a bit too neat.

As the programme does not explain which actor is which, I can only say that both the funny-looking one and the handsome one play their parts with admirable conviction and restraint. Short and sweet, this modest entertainment charmingly shows us that, like the dreamers we ridicule, we all risk more than broken bones when we leap into space believing we can fly.

To 9 Dec (020-7223 2223)