An elusive blackmailer is at work in London's high society. And the only person who managed to get on his trail - Sir Robert Gospell - dies under mysterious circumstances. The murdered man's friend, Roderick Alleyn, understands that he has only two days to find the killer. However, how can one identify the criminal among six suspects in forty-eight hours if there is enough evidence against each of them?.. A party of provincial aristocrats ended in a scandal - retired lawyer Harold Cartell accused those present of stealing an expensive cigarette case. And the next day, April 1, someone made a “successful joke” and killed Cartell... Roderick Alleyn, who was entrusted with the investigation, finds out that almost everyone who was at that party had a motive and the opportunity to get rid of the scandalous lawyer...