By John MacLachlan Gray

St. Martin's Minotaur. 285 pp. $24.95

This wickedly funny Victorian thriller opens with a most idyllic scene. The Rev.William Leffington Boltbyn, a mild-mannered, pink-cheeked vicar, is telling a story to two sisters, Emma and Lydia, ages 13 and 10. In his story, a fictional Emma follows a wayward croquet ball into a dark forest where she is menaced by brambles and meets a hedgehog who talks in riddles. When the vicar threatens to stop the story, the sisters plead for more, and he demands -- and receives -- kisses on both cheeks before he will continue.

The Rev. Boltbyn, we learn, writes children's stories and poems under an assumed name, and delights in photographing prepubescent girls as scantily clad wood nymphs and fairies. But Emma is his favorite -- the love of his life. It pains him immeasurably that she is 13, and soon "the golden light of childhood will die, and he will be alone, an orphan and a widower, at once." If you suspect that the Rev. Boltbyn is based upon Charles Dodgson, better known as Lewis Carroll, the author of "Alice in Wonderland," you're right -- the author proudly claims Dodgson as his inspiration. Both the vicar and the girls are soon threatened by as godawful a gaggle of cutthroats as ever darkened the sunny world of literature.

In the very next scene, on Sneer Lane, not far from the sewage-clogged Thames, we meet Robin and Weeks, veterans of the Indian army, who have just used chloroform to seize a young girl. India-born Englishmen, they had recently "arrived in London as destitute, unarmed and disoriented as Punjabis." They survived as "man-bashers" and "in the cadaver business -- stealing, digging up and, in a slow period, creating corpses" for medical schools. Then a Mr. Lush, reportedly "acting on behalf of a member of the quality," offered them a fat fee for "furnishing a young female subject for 'artistic purposes.' " Weeks, the enlisted man, is troubled by the assignment: "It is to crush the slavers [in India] only to become slavers oursel' -- and of an English girl." But Robin, the officer, has a grander vision: "It is not a sin, corporal. As in Bombay, it is an industry."

Next we meet our -- to stretch the term to its absolute limit -- hero, Edmund Whitty, a fearless, feckless correspondent for the Falcon. This once-celebrated journalist is now penniless and fears for his life. His downfall was his love of ratting. He thought that his dog Tiny was the finest ratter in London -- that, tossed into an arena filled with 50 starving rats, he could kill more than any other contestant. Alas, Tiny failed, and Whitty lost a wager, leaving him deeply in debt to the Captain, who sponsors ratting competitions at his pub, the Hen and Hatchet. The Captain not only employs rats for sport, he also uses them as debt collectors: "To recover his serenity over an overdue obligation, the Captain once locked a man in a cage with a hundred half-starved rats for three days." Dragged before the Captain, Whitty fears a similar fate but instead is offered a deal: The girl whom Weeks and Robin kidnapped was the Captain's beloved niece, and Whitty can settle his debt, perhaps save his life, if he will apply his journalistic skills to finding her.

Whitty's quest takes him to Oxford, where he encounters the pompous Rev. Charles Lambert, father of Emma and Lydia, and the clergyman's comely but unhappy wife, Birdie. He also encounters the arch-villain, the Duke of Danbury, who commissions the kidnapping and photographing of girls to feed his thriving pornography business. The duke, with his "cavalier ruthlessness, born of breeding," lusts for Birdie and even more so for Emma, whose "angelic childish face (with a most adult gleam of defiance in the eye)" brings out the worst in many men. The duke appoints the clueless Lambert to be "Spiritual Adviser to the House of Danbury," the better to ensnare his wife and daughter. There are echoes of "Lolita" here as the duke sets out to seduce the mother in order to bring the daughter under his control. There are echoes, elsewhere, of Dickens, "Sweeney Todd" and "The Threepenny Opera," as denizens of the Victorian underworld rob and kill but are never as venal as the blue bloods who rule the land.

Gray, a Canadian who introduced Whitty two years ago in "The Fiend in Human," takes the title of this novel from Lewis Carroll's habit of pasting a white stone in his diary to mark especially pleasant days. In the novel, the Carroll character, the vicar Boltbyn, remains on the fringes of the story for the good and simple reason that he's far too innocent to deal with the evil that surrounds him. As Whitty observes, Boltbyn "has never tired of childish things -- therefore desires to be with children in the way that a native desires to be with his own kind." Boltbyn, the duke, the Captain, Whitty, Emma -- all are delightful creations. If you have a taste for the sardonic, this sophisticated literary thriller is utterly delicious.