Taken at Midnight: 'A revealing and harrowing portrait of a good family in Nazi Germany'

The true story of Hans Litten, a German Jewish lawyer who subpoenaed Adolf Hitler as a witness in the trial of four Nazi stormtroopers in 1931, is a revealing and harrowing portrait of a good family in a bad place.

Trailing clouds of praise from Chichester, Mark Hayhurst's debut play sits well on the stage of the Theatre Royal. Among its themes is the test of moral principle when faced with Nazi barbarism and central to the story is Litten's mother Irmgard (Penelope Wilton, inset), a seemingly implacable woman whose maternal instinct gives her the courage to be "objectionable" to the Nazis in order to free her son.

According to Dr Conrad (John Light), the Gestapo officer she regularly visits, Litten has been put away for his own protection rather than as revenge for humiliating Hitler in the witness box. It's a lie of course. Incarcerated first in Sonnenburg concentration camp as a political prisoner and subsequently Dachau, Litten was tortured and abused.

Hayhurst shuttles the action between Irmgard's "discussions" with Conrad and the cell in which Litten is held along with two other "subversives", a newspaper editor (Mike Grady) and a self–proclaimed anarchist (Pip Donaghy). Given the nature of the subject there are flashes of humour that reveal human bravery even in the face of unimaginable cruelty.

Jonathan Church directs with a steady hand, perhaps too much so as I found myself drifting during the first act. The second half provides the best scene, Conrad out of uniform in a park airily discussing with Irmgard the differences in the way men and women respond to their children.

However a reenactment of the trial with Litten wearing a Hitler moustache is a lapse of judgment and the last meeting of mother and son in Dachau is oddly unconvincing. Not quite as essential as the subject matter demands.

Theatre Royal Haymarket, London 020 7930 8800, until March 14