This was Muriel Spark's fifth novel, first published in 1960 (this reprint dates from 1965)
In it, a group of thirty-something bachelors - a barrister, a teacher, a journalist, a museum attendant, a graphologist whose career has been ruined by epilepsy, a man obsessed with sex but riddled with religious guilt - roam around contentedly chatting in their London clubs. But soon enough, the men are variously tormented - defrauded or stolen from; blackmailed or pressed to attend horrid séances.
Patrick Seton, blackmailer, extortionist and supposed medium, plunges these men into the nastiest of lawsuits when he is accused of defrauding a widow out of her life savings. And as he faces his upcoming trial, he begins to gleefully plot the murder of his pregnant girlfriend.