Blue Sky, Hampstead Downstairs

Set at the start of the US and UK invasion of Iraq in 2003, Clare Bayley's Blue Sky follows an old-school journalist pursuing justice at the cost of neighbours and friends. Jane, played with careerist resolve by Sarah Malin, is convinced she has uncovered a case of extraordinary rendition. She believes the CIA are involved in the kidnap of a man seen being bundled on to a private jet in Islamabad so that they can question him under torture.

Jane contacts an old flame, Ray (Jacob Krichefski) to help her trace the plane, only to find he is more interested in getting back with her. No matter. With less charm, more bullying, Jane gets the information she needs. “Sometimes in journalism,” she says, “the ends justify the means.” A fortunate call from her editor then puts her in touch with a woman whose husband is missing. Jane is sure the stories are connected. Certain that her husband has gone off with another woman, Mina (Manjeet Mann) is reluctant to talk. Jane will not be stopped. Soon she is on the man's laptop, scrolling through his browsing history.

Theatre company Pentabus skilfully shatters any image of sleepy, bucolic England by homing in on the lives and fears of ordinary people in Shropshire during the war on terror. Ray and Mina know they must still pay their bills and look after their children even if Britain were to be directly attacked by Saddam Hussein. Ana, Ray's daughter (pictured right), is more politically-minded. A media studies student and blogger (much to the outrage of traditionally trained Jane), she cheerfully writes “Stop the War” on her face with eyeliner and goes on marches. Wearing slouchy clothes, Dominique Bull plays Ana with a refreshing, indomitable spirit.

Bayley invests her characters with long strings of novelistic back story. Jane's difficult childhood coping with her alcoholic mother explains why she resists relationships and prioritises her own interests, printing off plane logs behind Ray's back. Ray and Ana's past – his late wife, her mother, was an activist – explains why Ray is reluctant to be drawn into Jane's story (it conjures up too many memories) and Ana so keen to help.

This, however, is a lot to include in 80 minutes and the characters' baggage often hinders the plot. Following this play can be like following one of the jet's circuitous journeys with its numerous stopovers. Despite some fine performances and clever direction by Elizabeth Freestone, the story lurches unsteadily.

In one particularly chilling moment near the beginning, Jane (pictured left with Manjeet Mann as Mina) is seen thinking about the clues of her story while sorting through her mother's elderly possessions. A shoe and a toast-rack stand in for Johnston County in North Carolina and Cairo as she lays out the pieces of the puzzle. A plane thunders overhead; Jane's face is lit up; a phone rings. Then, towards the end, Ray tells Jane her jet is due to land nearby. This could have been compelling and exciting. But the chance is passed over. Instead, the focus jumps ahead to another scene.

Naomi Dawson's design makes visionary use of the runway-like stage between facing rows of seats. Ray's house is at one end; Jane's mother's house, bookended by an airport perimeter fence with its barbed-wire crown, at the other. Without blood-curdling screams or brutal words, the atmosphere in the swirling darkness is often spiked with menace and paranoia, even if the plot never delivers the terrifying scene at which it hints. Blue Sky might be unsettling only in parts, but the roar of planes will never sound so innocent again.

• Blue Sky is at Hampstead Downstairs until 3 November and at the Sherman Cymru in Cardiff from 13 - 17 November