Alistair Greenwood, Regius Professor of Modern History at Cambridge, hosts a luncheon at his faultless 17th Century home. Its perfection is marred by the incompatibility of the guests and the arrogance of the host. Gillian Adams, an American scholar revisiting the university while on sabbatical from Vancouver, finds it distasteful, but she's truly appalled when the eminent Greenwood is gunned down the next day while listening to her lecture. Involved as a witness, she's also hooked into the case by her friendship with Edward Gisborne of the Yard, who had come to hear her and remains to capture Greenwood's killer.