Taking Care Of Baby, Hampstead Theatre, London

If there is anything worse than losing a child, it's being accused of having murdered the child. And if there is anything worse than that, it's being charged with having murdered two in succession. This is the position of Donna McAuliffe, the young mother at the centre of Taking Care of Baby, a powerful and distressing new drama by Dennis Kelly. Obviously influenced by the cases of Sally Clark and Angela Cannings, both jailed because of expert testimony that proved to be flawed, the play poses as a piece of verbatim drama. The statement that "The following has been taken word for word from interviews and correspondence" passes several times across the screens surrounding the effigy of a baby on Patrick O'Connell's set.

Intoning questions like the disembodied voice on Channel 4's Big Brother, the unseen dramatist interrogates the characters in Anthony Clark's sparely staged and very well judged production. This author-figure is openly accused of being a parasite rather than a truth-seeker, for this is a play that is prepared to implicate itself in the mechanisms of injustice.

The play doesn't seem to be proposing the idea that all truth is subjective. Rather, it fixes on a scenario where innocence is agonisingly difficult to prove and why the truth will always be a matter of dispute because of the competing agendas of the people involved. The estranged husband (Nick Sidi) is the best handled of these witnesses. We see him giving testimony and outlining the reasons (his wife's post-natal paranoia that alternately made her over-protective and neglectful; her dubiously exact instinct that the second baby had died) why he believes she is a murderer.

By contrast, the other characters are vividly drawn but crude. The medical expert Dr Millard (Christopher Ravenscroft) seems to have self-interested motives for continuing to endorse the discredited Leeman-Keatley Syndrome. And we're subjected to far too much detail about the ambitions of Donna's mum (Ellie Haddington), a local councillor who thrives on the media attention as she rises to become a parliamentary candidate.

Abigail Davies delivers a stunning performance as the now-released Donna - heartbreakingly direct yet elusive as she struggles with several kinds of grief. When she announces at the end of the play that she is expecting another baby, the frisson of anxiety that passes through the audience shows the burden of suspicion that she is doomed to carry.

To 23 June (020-7722 9301)