Nick Stafford has written a bleak and powerful play about loss and belief which marks a return to form for the Rep's new writing strand in its studio theatre.

David, desperate to discover the truth about the disappearance of his daughter Katherine two years earlier, attempts to enlist the help of Kay, who has recently started visiting Kevin, an old acquaintance who has been imprisoned for a series of rapes and murders.

Kevin, who protests his innocence, has not been linked with Katherine's disappearance, but CCTV places him in the vicinity at the time she disappeared.

Since Kay believes in Kevin's innocence, David's approach is initially unwelcome, while he has to overcome his instinctive contempt for her. The play follows their progress towards an unlikely, mutually-supportive friendship as additional perspectives are added: we discover that Katherine once attempted suicide, and that Fay's husband is also "missing", having retreated into a comatose state as a result of a mystery illness.

Directed by the Rep's former associate director Gwenda Hughes, the play is given a pleasingly spartan production featuring a real Door rarity - a raised stage. In a dark spotlit space there are just four actors - the above characters and a prison guard - and some chairs.

Scenes move swiftly between the prison, the places where David and Kay meet - a park and a bookshop - and the hospital where he voyeuristically discovers the truth about her husband. There are evocative touches of sound and projection.

Though clearly not a light comedy, this is not as gruelling as Bryony Lavery's Frozen, another play originating at the Rep with which it has something in common, nor does it rise to the same emotional heights. But it is a gripping and interesting piece of work, very well played by this cast - particularly Paul McLeary as David, the most unremarkable of middle aged men, transformed to his own bewilderment into a dogged obsessive.

* Running time: Two hours, ten minutes. Until May 27.

Terry Grimley ..SUPL: