The President of an Empty Room, NT Cottesloe, London

This livens things up, at least. Your shins feel the breeze from the bale-shifter's passing trolley, loaded with tobacco, and from the bike which one cigar-roller pedals round the shop floor. Later, there's a bout of tangoing, virtually in your lap, and chairs and sandals are sent flying when tempers fray. I did toy with the idea of seeing whether the voodoo spirits - who wander in occasionally - would pass straight through my feet, but it wasn't worth the risk.

In spite of the intimacy and detailing of Bunny Christie's beautifully dilapidated set, Knight's script proves bizarrely tedious. That's mainly because the plot is a kind of theatrical smoke ring, centring round a beautiful young worker, named Alexandra, who has escaped before the play begins and hence never inspires any real interest. Her friends worry endlessly that the boat she has boarded, hoping to reach Florida, will be caught in a storm, and her ex-boyfriend, Paul Hilton's Miguel, is half-crazy with grief and heroin, sardonically declaring himself the president of what's left while the boss is away. He proclaims the shop floor a democracy where, instead of quarrelling, everyone can collectively vote to listen to Michael Jackson on the radio, folk songs on cassette or, maybe, a live violinist like the ones employed by the factory in the old days. A menacingly mute tramp is found who is prepared to play the fiddle, so they have a mini-fiesta. However, Miguel is dictatorial and keeps verbally lashing out. Dona Albina is officially meant to maintain staff morale by singing, but she has also consulted a voodoo doctor. An ancient crone who collapses in the midst of their dancing is, supposedly, a witchy spirit from Alexandra's sinking ship.

Obviously, the fading poster on the wall, picturing Castro puffing a cigar, indicates Miguel's democracy might be compared with the bigger political picture. Knight's dialogue repeatedly underlines his other themes, too: fictions versus repressed truths; reason versus superstitious fears; the Americanisation of Cuban culture. At the same time, this dramatist's ideas are irritatingly hazy, if not ultimately vacuous. Though Knight recently won awards for his screenwriting debut, Dirty Pretty Things, here the lack of character development and narrative drive is woeful. The rusty, slow-moving fan embedded in the factory wall merely adds to the sense of stagnation. To give Davies' cast their due, the ensemble playing can be natural, humorous and vibrant. Fraser James is magnetic as Miguel's generous-hearted but taunted gay pal, Simon, and Hilton exudes febrile bitterness without going over the top. Nonetheless, Jim Carter is stolid as Alexandra's father and the supernatural elements completely lack conviction.

Given that we've had to suffer two disappointing plays about Cuban cigar factories in the last six months - the first being Nilo Cruz's Anna in the Tropics - one might start developing feverish conspiracy theories about tobacco magnates taking to covert theatrical advertising. But it's not the on-stage smoking that makes this show a stinker. It should come with a government health warning about being bored to death.

k.bassett@independent.co.uk

To 27 August, 020 7452 3000