An English Tragedy, Palace Theatre, Watford

At 74, Ronald Harwood is showing no signs of slowing down. He's just won a Best Adapted Screenplay Bafta for The Diving Bell and the Butterfly and he may soon be picking up a second Oscar (his first, in 2002, was for The Pianist). Before that, though, he has unveiled his latest stage play, An English Tragedy, in a powerful production by Di Trevis at the Palace Theatre, Watford.

It might look a shade incongruous that a drama with this title is performed on a swastika-shaped stage (the set is by Ralph Koltai). But the focus of Harwood's engrossing, eloquent play is the British fascist John Amery, who was arrested and charged with high treason in 1945. What gives the trial its fascinating twist is that the 33-year-old prisoner in the dock was the son of Leo Amery, a senior Tory, close friend of Churchill and former Secretary of State for India and Burma.

In mounting a case for the defence, John's connections were both an asset and a liability, but all efforts were rendered futile when he pleaded guilty. Did he do so to spare his family embarrassment? Or was there a deeper reason? And did his son's conviction prompt any soul-searching in Leo?

Richard Goulding vividly communicates the weird emotional disconnectedness of John, who flounces round his cell and talks to his teddy like an anti-Semitic version of Sebastian Flyte. He also suggests that this pansexual embezzler, alcoholic, bigamist and fantasist is a lost, pathetic figure. Determined to spearhead a crusade against the twin evils of Jewry and Communism, he toured the Allied prison camps recruiting for his soi-disant League of St George, but he only managed to scrape up 57 volunteers. Even his Nazi pals took exception to his drunken sexual escapades.

The play explores the terrible price of concealing one's true identity and living a lie. Jeremy Child as John's father conveys the agony of confronting the fact that his refusal to acknowledge in public key aspects of his heritage may have helped drive his son into self-hating extremism. Diana Hardcastle is heartbreaking as the doting mother. A thought-provoking drama with a compelling subject.

To 8 March (01923 225 671)