Maurice Sendak (1928-2012) cultivated an image as a curmudgeon. He had a particularly good, cranky run in the last year of his life. He appeared on “The Colbert Report,” ripping the current crop of children’s books as “abysmal.” He was interviewed by Emma Brockes in The Believer magazine, and he declared about e-books: “I hate them. It’s like making believe there’s another kind of sex. There isn’t another kind of sex.”

Anyone who’s spent time with Sendak’s best books – “Where the Wild Things Are,” “In the Night Kitchen” and “Nutshell Library” among them – knows that this querulousness was the salt crust on a deep and complicated well of feeling.

Sendak’s posthumous new book is “My Brother’s Book,” written in memory of his brother, Jack, who died in 1995. This lovely if evanescent book also feels like an elegy for his longtime companion, Eugene Glynn, who died in 2007. The line that hangs over it, spoken by a young man who has lost his brother, is this: “A sad riddle is best for me.”

At the beginning of “My Brother’s Book” a great screaming comes across the sky. A new star slams into Earth, separating two brothers, Guy and Jack, and heaving them out of paradise. Jack is catapulted “to continents of ice.” He is “a snow image stuck fast in water like stone./His poor nose froze.”

Guy, meanwhile, goes tumbling down into “soft Bohemia” and into the lair of a polar bear who threatens to eat him “bite by bite.” Guy ultimately does allow the bear to devour him. In death he goes “sweeping past paradise” to rejoin his brother.

“My Brother’s Book” has echoes of Shakespeare’s “Winter’s Tale,” the play that contains the stage direction “Exit, pursued by a bear,” and it contains some of Sendak’s richest and most incantatory language. When Guy poses a sad riddle the bear cannot answer, we read:

To hell with you then!” the bear uproared,

Shadowing the sky, bellowing up a whirlwind

And slanting wide the world to the winter side –

And with his mighty paws scattering himself

Into a diadem of noble stars

Befitting Ursa Major.

Sendak told Stephen Colbert that he never really wrote for children. “I write,” he said, “and somebody says, ‘That’s for children.’ I didn’t set out to make children happy.”

“My Brother’s Book” will probably not make many children happy. It’s an elegiac volume that has little in the way of story; the hero isn’t as winsomely bossy and obnoxious as Sendak’s characters often are.

I disliked it my first time through; I found it a bit evasive, more artiness than art. I wasn’t sure that I cared about Jack or Guy. Yet it’s a book that rewards repeat readings. Its charms are simmering and reflective ones. This moral fable may find its largest audience among adults.

Sendak’s drawings in “My Brother’s Book” have lost none of their surreal, unsettling potency. The influence of Marc Chagall, always apparent in Sendak’s work, is on display here as well.

Guy does not rise into heaven after being consumed by the bear. Instead Sendak writes:

Guy sank upon a couch of flowers

In an ice-ribbed underworld

Awash in blossoming gold from a new sun

Tumbling out dark long-ago clouds,

In caverns and corridors paved with painted petals

Wound round a wild cherry tree dusted pink.

In his foreword to “My Brother’s Book,” the Shakespeare scholar Stephen Greenblatt notes how Sendak seems to have picked up on Shakespeare’s evocation, in “The Winter’s Tale,” of “unpathed waters, undreamed shores.”

I was put more in mind of a line from “Mansfield Park,” in which one of Jane Austen’s characters declares, “What strange creatures brothers are!”