Smith is an outstanding book on many counts. Set in the author's favoured period, the mid-eighteenth century, the story owes its unerring sense of period partly to the characters. But though they are, you might say, period types … they transcend costumes, idiom, manners, because the author uses them to communicate more than just a sense of the past. This intricate mystery of ancient wrongs and present revenge has the kind of tempo and vitality we expect from Leon Garfield. Adventure is here, initiated when Smith … witnesses a murder seconds after he has snatched a document from the pocket of the victim. What the document holds, how Smith worries at its secret and what danger his curiosity brings—explanations follow logically on event in scenes in Newgate, in the streets of Holborn, on Highgate Heath—and for these scenes the author has first worked at background facts and then...