Leon Garfield seems to have had no 'prentice period. His first book, Jack Holborn …, has all his characteristic qualities; indeed if one were to be unkind one might venture to say that he has gone on telling the same story ever since…. [The book includes] mutiny, shipwreck, jungle trekking, a slave-market and a great trial scene. The ingredients are all conventional enough. It is the author's expert chemistry—appropriately he is a biochemist by calling—which makes the unpromising materials react to produce tension and atmosphere.

Jack Holborn is sustained through great physical ordeals by the hope that he will discover his identity…. When the truth is made known … it is unspectacular. Jack's mother is not a duchess but a treasure of a housekeeper to a foolish Sussex knight. In Devil-in-the-Fog … the situation is reversed. George Treet, one of a travelling showman's brood, discovers early on that he is in fact the long-lost son and heir to a wealthy Sussex knight…. At last it appears that he is not the heir, but that he has been called upon to play a part with innate professionalism.

What makes these absurd plots not merely acceptable but absorbingly fascinating is Garfield's craftsmanship. He has a gift for creating sharp larger-than-life characters, like Mister Solomon Trumpet in Jack Holborn and Mr Thomas Treet, genius and loving father who allowed his infant son to be scarred for life in return for payments down and to come, in Devil-in-the-Fog. He excels in equivocal characters, leaving the reader to puzzle through the course of a long story whether they are good or evil. More important than characterization is style. Written in conventional modern English, these stories would scarcely find a reader, let alone a publisher. But Leon Garfield tells his stories in an extraordinary evocative language all his own (it is no more the language of the Eighteenth Century than Jeffery Farnol's equally artificial stylistic mannerisms were). Garfield hypnotizes the reader, wooing him with strange sounds and haunting circumlocutions into a willing co-operation. The words are like an incantation. Archaisms abound, and common words are disguised as unfamiliar contractions—'to've' and 'so's'. The pressure never eases. Garfield has remarkable skill in focusing attention on a situation or a character by a telling description. When Jack Holborn sees for the first time the agent of Nemesis—characteristically in the fog—'he never spoke nor nodded nor waved to any living soul, but stared and stared across the dirty sea as if he was looking for a particular wave.' Here the device is effective and functional, but at times it seems a form of self-indulgence or exhibitionism. (pp. 34-6)

Leon Garfield's craft is at its most brilliant, and is most at the command of his theme, in Smith…. In this story of a 'sooty spirit of the violent and ramshackle town' and of the London underworld the stylistic mannerisms are comparatively subdued, and the story moves almost as swiftly as Smith, beside whom 'a rat was like a snail'. Smith is a fine creation, a most complex blending of apparent contradictions…. In this book there are qualities lacking in most of Garfield's work, compassion and involvement. It is not just a masterly exercise in story-telling, but a book through which the reader shares in the triumphs and disasters of Smith and his admirable sisters, Miss Bridget and Miss Fanny…. (pp. 36, 38)