Thandie Newton, making a West End debut at the Harold Pinter formerly known as the Comedy Theatre, has big boots to fill in Death and the Maiden, following Juliet Stevenson in the role of Paulina Salas, a rape and torture victim in Pinochet’s Chile who corners her supposed tormentor in a beach house shortly after her lawyer husband has been appointed to a government amnesty commission.

So how does she do? She works hard and gets through it. But her voice is severely limited in range and colour and her emotional register underwhelming. Whereas Stevenson tore you apart, Newton presents a doll-like figure, wielding a handgun as big as her head, barking out her rage and sense of injustice with the pettiness of someone who’s been short-changed at a supermarket check-out.

For the first few scenes of Jeremy Herrin’s otherwise sleek production, smartly designed by Peter McKintosh, with piles of pebbles on the forestage and crashing waves in the auditorium, you feel the play would be better as a film (and it was a film care of Roman Polanski, with Sigourney Weaver and Ben Kingsley). But then Dorfman’s plotting and complexities of argument kick in and the tension builds all the way to the ambiguous conclusion.

Is it time to forget or open old wounds? Does an eye for an eye have any humane, or even moral, force? Are the right people being brought to justice? What is the appropriate treatment for torturers? And how much can we trust confessions elicited under duress?

Paulina is treated like a second-class citizen even at home. The alleged tormentor is encountered by chance after an act of generosity on his part. And the husband has not been a perfect partner. The consequences of this episode in the play could destroy the commission formed to deal with a post-dictatorship healing process.

In the end, the battle is to save a marriage, exorcise ghosts, reclaim the Schubert string quartet of the title which the doctor played to his victims. Newton looks happiest onstage in the little black cocktail dress she wears for the concert at the end. You never feel moved by the character’s memories of abuse, her years of suffering, her super-charged zeal that even allows a mention of madness.

Herrin gives her two fine actors in support: Tom Goodman-Hill as her husband, Gerardo Escobar, weaves sinuously in and out of the fast-changing situation; and Anthony Calf as the doctor, Roberto Miranda, plays a deft hand at self-defence in the most unflattering pair of boxer shorts I’ve seen on a West End stage.