In 1749, clever and uptight finance director Israel Rubenstein is deeply unsettled when the enchanting and manipulative duchess Sophie demands that he speak to her husband about the fulfillment of his marital duties. The proud teenage duke Wilhelm has a severe phimosis, making coitus very painful and deterring him from the politically important consummation of his marriage. A circumcision would solve the problem, but no one has yet dared to make this daunting suggestion to the choleric duke. Fed up with waiting, Sophie forces Rubenstein to do so because she is convinced that the Jew should be an expert on the matter. The nervous finance director and the temperamental ducal couple meet for a precarious cup of tea and the embarrassing topic soon raises tensions. Rubenstein has to rise above court etiquette and his own insecurities in order to save the ducal marriage and his own head.