From “The River Bank,” by Kij Johnson, a sequel to “The Wind in the Willows.” (Kathleen Jennings)

If you’re going to write a sequel to one of the most beloved children’s books of all time, you’ll need to be pitch perfect, hit all the right notes and, at its end, leave your reader shouting “Bravo!” Or in this case, “Brava!” and “Encore!” Kij Johnson has brought out an absolutely delightful book, as charming and funny and rereadable as Kenneth Grahame’s “Wind in the Willows” itself.

“The news was everywhere on the River Bank and had been heard as far as the Wild Wood: Sunflower Cottage just above the weir had been taken by two female animals, and it was being set up for quite an extended stay. More, it was being done properly, the River Bank’s housewives agreed. There was none of this casual, slapdash housekeeping that bachelor gentlemen were so apt to consider sufficient.”

“The River Bank,” by Kij Johnson (Small Beer Press)

Harrumph — females! Won’t they upset the easygoing life along the river? The Mole, the Water Rat and old Badger are set in their ways, plus there’s no telling what effect these two young ladies — a mole named Beryl and a rabbit named Lottie — might have on the volatile Toad. Ever since the battle of Toad Hall the year before, its master has been behaving with relative propriety. Of course, Toad being Toad, he now regards himself as that conflict’s glorious champion:

“Over the mantel, the Toad had caused to be mounted a tasteful arrangement of crossed swords and pistols, clustered appetizingly on either side of a large painting in a gilded rococo frame, of a mighty Toad brandishing pistols in each hand, vanquishing quite a crowd of Weasels, Stoats, and Foxes, as a rather smaller Badger, Mole and Water Rat looked on admiringly from the corners of the picture. There was some sort of thunderstorm going on in the background, and a bit of sunlight breaking through managed to illuminate the Toad while leaving everything else in gloom. A small brass plate affixed to the frame read, The Valiant Toad, Amidst the Fray.”

Beryl, it turns out, is an “authoress,” whose novels include “The Haunted Treasure of Bone Island,” “The Iron Hare of Chateau Sang,” and the chillingly suggestive, “M. Bourne, Vivisectionist.” She is now at work on a new book, tentatively entitled “Philotera’s Horror”:

“There was a calm yet plucky heroine; a locked battered iron box with a missing key and mysterious runes scratched across its lid (perhaps cursed; Beryl hadn’t decided yet); a ruined estate in Cornwall (for research she was relying heavily upon a souvenir folder of tourist postcards entitled ‘Scenic Cornwall, Land of Tintagel!’); an ancient sage who existed in the novel solely to pass on to the heroine a forbidden secret of mind-control, and immediately afterward to die before her horrified eyes; a poisonous serpent being kept as a pet in a basket in the villain’s lair (which Beryl knew would come in handy for the plot at some point); and an endangered orphanage filled with children that reminded the heroine of herself when she was a lass.”

Soon Toad and the naive Rabbit — as Lottie is usually called — begin to spend time together: He shows her his ruined caravan and wrecked motorcar, relates some of his many adventures and gradually reveals, with his usual becoming modesty, that he is “a Hero, plain and simple: clever, cunning, and courageous.” Alas, his days of adventure are over. Or are they? One fateful morning Toad receives a telegram delivered by a motorcycle messenger, who “sat casually astride his glorious machine, like the conqueror Alexander upon his noble mount Bucephalus, or Perseus astride the divine Pegasus, or — well, there were all sorts of comparisons possible.”

Toad immediately knows that he must, absolutely must, acquire a motorcycle, “the largest, most powerful, and most dangerous possible.” However, there’s a problem. Because of his past crimes, which have marked him as “a villain stained to the very bone and a conscienceless recidivist,” Parliament has prohibited dealers from selling him any kind of motorized vehicle. How he, ahem, obtains a Dustley Turismo X is a dazzling, hilarious set-piece, but then he is, after all, “the unstoppable Toad.” Soon the master of the open road once more, he zooms along, with the Rabbit hanging on for dear life, singing his own praises: “Who escapes from every trap? Toad: only Toad! Who slips from their grasp, yet again? Why, they all cry, ’tis Toad! . . . Sly as a fox and twice as smart!”

A period-style drawing from “The River Bank,” by Kij Johnson and illustrated by Kathleen Jennings. (Kathleen Jennings)

Still, the newspapers go wild: “Notorious Toad on the Rampage! Valuable Motor-Cycles Destroyed, Stolen, Young Rabbit Kidnapped by Vile Amphibian, ‘They Could Be Anywhere,’ says Scotland Yard.” Naturally, disaster soon strikes this runaway pair, but I will say no more, except to add, most emphatically, that all of it is wonderfully told, that Lottie is more resourceful than she seems, and that Mole, Water Rat and Badger help save the day.

At times the comedy of “The River Bank” recalls that of a witty Georgette Heyer novel, complete with misunderstandings, letters that go astray and an unexpected, gently feminist denouement. Beryl’s thoughts about her novel aren’t just funny, they also reflect the way books obsess their authors, as Johnson — herself an award-winning science fiction writer — clearly knows: At one point Beryl even criticizes the grammar and lack of clarity in a ransom note. Not least, there are occasional intertextual nods, as when Toad’s motorcycle narrowly misses “a nun incautiously leading a double file of small girls in yellow hats,” one of them doubtless named Madeline.

One final, important point: Kathleen Jennings’s period-style illustrations add just the right extra magic to make “The River Bank” a complete triumph. If he were still around, Kenneth Grahame himself would be wildly applauding.

Michael Dirda reviews books on Thursdays for Style.

the river bank
A Sequel to ‘The Wind in the Willows’

By Kij Johnson

Illustrated by Kathleen Jennings

Small Beer. 195 pp. $19.95