Thousands of years ago the Hilda Lini landed on the world of Heven carrying a cargo of passengers from Earth's South Pacific region. Heven was the first planet they had come across that would fit the kastom of the people. The only major difference from the Earth was in Heven's clouds.

Kalbaben wants to fly but it is tabu, forbidden by whatever it is that lives up in the clouds. Over the centuries all knowledge of flight has been lost. When Kal and his friend Vira build a giant kite and she sails forth in it, the clouds amass and she is struck down. Kal is exiled from his native island of Epi to Tanna, where he discovers that he is the subject of a prophecy. He also befriends Bani Voko Voko Leo, who seems to know a lot more about the prophecy than Kal himself does.

In the first chapter of Cloud Permutations we learn that Kal's story, whatever it may be, has passed into legend. "The magician's name is not recorded. This, in the history of Kal, is merely an oral account, and may be apocryphal" (p. 5). It's a format that allows the narrative to leave plenty of gaps, gaps that its ostensible readers, the inhabitants of Heven, would easily be able to fill. I'm not sure if the author is intentionally taunting us with our lack of knowledge here—when he begins his final chapter with "[k]nowing the end of a story does not make it easier to tell" (p. 115) I begin to suspect that he is. But this format also allows the narrative to constantly comment upon itself, questioning its own sources and the veracity of its own statements. "There are contrasting stories regarding that first conversation" and (on the same page):

As to its contents: sources are . . . divided. Moli Solomon did not, after all, register her prophecies. She was, when it came to it, a water worker. She was open to the influence of clouds. She was hardly, in other words, a reliable witness to the future. For Kal, she drew the tower, and a fall. For Bani . . . sources are still, after all this time, divided. The argument rages on. Did he know, or merely suspect? (p. 34)

It is with the introduction of Bani that the book first diverges from the path seemingly set for it—that of the young hero coming of age, discovering the world and doing something heroic (in this case, presumably, exposing the reasons for the taboo against flight). From this point on Cloud Permutations tells two stories, and of the two Bani's is certainly the more tangible. Bani is also a child of prophecy. Both prophecies involve a black tower—Bani is seen sailing in its shadow while Kal falls from its heights. But if Kal dreams of flying, Bani wants to know things. It is Bani who drags Kal into an ill-fated expedition to discover more about the former inhabitants of this world. Bani finds ancient maps, has conversations with impossibly old artificial intelligences, and discovers that their enemies are a mysterious organization known as The Guardians of the Tower. Of the two, Bani is the one who will materially question the injunction against flight, and will change the lives of Heven's inhabitants. For most of the book, he is the character performing most of the action. "He acted, while he, Kal, could only lie there and feel that he was cargo" (p. 106).

Yet this is Kal's story, and that means that the reader can only ever piece together bits of Bani's. In part this is because Kal seems content to drift along without knowing much; consider this passage, midway through the book.

'This sea is the last of its kind,' the Other was saying. 'For aeons I've sat here, trapped and alone, computing probabilities. The water here is like the water of the clouds, molecular structure . . .' he droned on. Bani seemed riveted. Kal grasped the stick and thought of rising from the water and taking to the air. He would fight the clouds, he thought. He would fly and blast at them, breaking through, rising as high as you could go, until there was only space . . . (p. 72)

Later, the contrasting reactions of the two boys to the tower are telling:

It filled their vision: a huge towering block from the earth to the skies, a granite monolith that blocked out the sun. 'How would you build something like this?' Bani said. He was talking mainly to himself. 'It would require an entire landmass just to provide the basic material.'

Kal didn’t care. To Kal, the tower was built with black stone and smoke and storm clouds. (p. 109)

Almost it feels as if these two stories belong to two different genres. When occasionally questions are raised about Heven's history, it is understood that they are not going to be answered. "What had transpired, in the intervening centuries since Heven was found, to erase the memory of [the Hilda Lini's] landing so?" (p. 81). This is the sort of thing Bani's story, if it were told, would answer. And yet most of the story is told from Kal's perspective. We shift rapidly between being told exactly what Kal thinks, feels, and dreams at a particular moment to being reminded that even the narrator does not have all of the facts.

The episodic nature of the narrative adds to the feeling that these events are merely incidents in the life of Kal, rather than forming a coherent plot of their own. There's no narrative to connect the boys' horrifying experience on the island of the Narawan, their encounter with the people of the Migdal ("tower" in Hebrew) tree and the final journey north to the Tower. One occasionally gets the sense that Kal has become the sort of mythological figure about whom multiple stories are told, without these being in any particular order to form a biography of his life. The possibly "apocryphal" story with which Cloud Permutations opens only adds to this sense.

The culture of Heven is connected to the earth ancestry of its people in numerous small ways—the ship named after Hilda Lini, the town named after Jon Frum. The most noticeable of these is the use throughout the book of Bislama; phrases in the language are used to title each chapter and pop up frequently in the text.

I'm not sure why Tidhar needs to explain that Bislama is "the old language of the islands of Earth . . . a language that had evolved from English vocabulary and Melanesian structure, the Esperanto of the South Pacific Ocean back on old Earth" (p. 26). The similarity to English makes it tempting to attempt interpretation. This is simple enough at first—the Bislama phrases that title each chapter generally occur soon after in their English translations. But not every meaning is freely given, and it's unclear whether this is a reminder that Bislama is a language in its own right and not that accessible, a continuation of the book's policy to tell us as little as possible, or both. Much of the appeal of the Bislama here is also in seeing how familiar phrases translate; to know that "Ol smol grinfala man oli no blong ples ia" (45) are "little green aliens," or to read Tidhar's translated verses of "Kubla Khan" onto the original.

Coleridge is one of a few writers to be mentioned by name—others include Cordwainer Smith (in a reference to a "Cord-wainer tower," p. 115) and an Israeli poet with suspiciously familiar initials, Lior Tirosh (who has appeared in other works by this author). But there are certainly references to other works. Lovecraft gets a nod, with the "Bigfala Olfala Ol Ting" (p. 47), "Olfala Bigwan" (54), or Great Old Ones, who seem to have lived in Heven's seas in the distant past. Less directly there's a possible nod to H. Rider Haggard and a whole tradition of Victorian adventure stories involving lost civilizations and nameless immortal wonders. It's unfortunate that pastiching these works means here to an extent replicating their gender politics—besides a brief appearance by a water worker and mention of an aunt there are two women in the book, and they both move the plot forward by dying.

The references to other works may just be Tidhar's fondness for pastiche, but they fit well here with the various meditations on stories and how they are told, and how they are left untold. Cloud Permutations is fascinating and infuriating because it is about its own failure to tell its story. Until the end it is reminding us that we "still cannot talk with, nor understand, clouds" (p. 119), and Kal's story must therefore remain a mystery.