When in Rome

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. 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. Inspector 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…