There’s promise in this new Sound Dust venture in the bleak, black upstairs room of a ramshackle Irish pub on the Kilburn High Road, but the play, Invisible Storms, devised and directed by Jamie Harper and Dan Muirden – the first a winner of the 2006 JMK Directors’ award, the second a graduate of the Royal Court Young Writers’ programme – needs writing out properly.

At the moment, a good plot - about a Norfolk farming family exacting revenge on a government agency environmentalist for refusing them a protective sea wall - emerges haphazardly through a series of story-boarded scenes improvised each night by the actors.

The best scenes are the ones of edgy comic embarrassment as Sarah-Louise Young’s “Polish cleaner” inveigles herself into the Kilburn house where the offending apparatchik – the head of the farming family has committed suicide in despair after sending ten years’ worth of unanswered letters – lives with his mother (Carrie Jones).

This is the second play opened in a week to play the climate change card, and in Norfolk too (the first was Steve Waters’ infinitely superior The Contingency Plan at the Bush), and it’s a chilling moment when we’re told that a sea wall costs £4,000 a metre to build, and that the Norfolk farm is in a low-priority, low-yield area.

Benjamin Peters dithers impressively as the political baddie, sucked into an emotional involvement that has a good tragic twist, and Richard Atwill and Hywell John have a good shout from different perspectives on the issue. The character who comes off worst is poor old Mum, required to switch priorities at alarming speed, and finally dispensed with too quickly.

The demands of the story-line mean that real improvisation is necessarily limited, and once the point of a scene is established, there seems to be too much flab and muttering as the actors strive towards the next narrative emphasis or lighting cue. But there is at least something lively going on here; the Harper/Muirden work may yet be worth watching out for.

- Michael Coveney