It was April in Rome, and gathered together in the church of San Tommaso in Pallario was the kind of varied group of people that can only meet on a tour. It included a superannuated jetsetter and her junkie nephew, a bad-tempered, ultra-British major, a boisterous Baron and Baroness, and an extremely reticent best-selling author. They were there under the aegis of one Sebastian Mailer, who had promised them a most unconventional tour—a claim no one later disputed, after encountering murder, blackmail and drug-running.
Superintendent Roderick Alleyn, in Rome on a special mission, became involved in the case, and found it one of his most baffling—a case in which every suspect might equally well prove a victim…