How does a good man become evil? And can he cross the line without even realising it?
Professor Halder appears to be a good man. He is a genial academic, struggling with his own mental health, an inadequate wife, a flirtatious student, an ailing, suicidal mother and a best friend who happens to be Jewish. He is essentially moral, or so it seems. But this is Nazi Germany. Somehow, imperceptibly at first, he becomes sucked into Hitler's killing machine. He is flattered and cajoled into implementing a euthanasia programme for the old and incurable. Next thing, he is burning down synagogues.
By the time he takes off his beige suit to don SS jackboots and uniform he is beyond redemption.
On paper it sounds very dark. But this is a genuinely gripping production, buoyed by laugh-out-loud moments of black, black comedy, and bizarre musical interludes that form part of the delusions plaguing Halder.
This is a marvellous directing debut at the Royal Exchange for Polly Findlay. She starts with chaos, an apparent pandemonium of overlapping scenes, but quickly resolves the production into something that is amusing and disturbing in equal measure.
C P Taylor wrote Good at the very end of his prolific but all-too-short career as a playwright. He was born into a Jewish family in Glasgow, lived as a socialist, suffered for his art - he got pneumonia writing in his garden shed - and died a Christian.
Adrian Rawlins plays the good guy professor corrupted by Nazism. His very ordinariness marks him as an everyman rather than a born monster.
His best and only friend is Maurice (Kerry Shale), a sardonic and slightly self-hating Jew.
Halder betrays him, as he betrays his wife, children, academia, morals and much else. Even worse, he attempts to justify what he call his "temporary racialist aberration".