Tom Bell, who in 1979 created the role of Horst in Martin Sherman's play about Nazi persecution of homosexuals, died the night before this revival opened. His 2006 counterpart, Chris New, lacks Bell's flintiness but turns in an excellent performance in what is apparently only his second professional stage outing. New is entirely believable, and affecting, as a man trying to survive life in Dachau without sacrificing everything in himself that makes living worthwhile. The contrast is with Max, who metamorphoses from flamboyant Berliner gay-about-town to someone who will deny everything for survival, even telling of how he raped a teenage girl in order to "prove" his heterosexuality and so earn a yellow star, at least one step in camp hierarchy above the pink triangle. Time and again, however, Max fails to suppress his essential character, his very identity.

This production's main commercial attraction is the reappearance on a British stage of Alan Cumming as Max. Cumming's instinctive pertness rings interesting changes at some points in the evening, as when he describes the purpose of pointlessly moving rocks from one pile to another and back as being "to drive us maaad", with a daft whoo-whoo inflection. It's not this playfulness that is his problem, but rather the fact that he is too emotionally eloquent an actor. Even from row K of the amphitheatrical main Trafalgar Studio, one can clearly see every spasm of fear, revulsion, tenderness and despair cross Max's face. It is an admirable performance, but it doesn't fit the script: if we can see Max's true feelings so easily, how does he conceal them from his jackbooted oppressors?

The other problem is that director Daniel Kramer has chosen to make his Nazis real monsters: whooping, bellowing, revelling in their inhumanity. It makes for a lot of terror (even during scene changes, as furniture is simply hurled into pits on either side of the stage – the débris of civilised life piling up), but at the expense of more potent moral horror. In an age when various proscriptions are being enacted against confected categories of Other, what we need to remember is that the black-uniformed tyrants were human beings as ordinary as we are, and that conversely we may be no different from them. Humanity is not the sole preserve of the two men shown standing to attention during a work break, making love with words only, never even touching. Dachau was a minor camp; it is now generally believed that only (only!) 30,000 or so people died there. If this production plays to full houses for the entirety of its run, it will barely be seen by as many people.

Written for the Financial Times.