The internal consistency of the imagined fantasy world—or in Tolkien’s language, the world’s “sub-creation”—is vitally important. Indeed, one can track the path of the Fellowship of the Ring day by day as they journey toward Mordor across a land so gloriously detailed that it seems real. Although Middle Earth is an invented place, its history now spans more than 12 volumes and, until this year, was still being written. The grittiness and verisimilitude of Martin’s A Song of Ice and Fire series, with its politics, intrigue, and gruesome deaths, is all-consuming. The Lord of the Rings and A Song of Ice and Fire are works of escapism, doors through which one can enter the perilous realm and not emerge for days.

In The Last Unicorn, there are no maps, invented languages, genealogies, or epic battles. Instead, there is just the nameless unicorn in her “lilac wood,” where “she had no idea of months and years and centuries.” There she would no doubt have stayed forever, if not for the stray remark of passing travelers who speculate that there are no more unicorns left in the world. So the unicorn sets out to find others of her kind, who she soon learns are being held captive by the miserly King Haggard and the mysterious Red Bull. Along the way, she acquires traveling companions: the hapless magician Schmendrick and the bitter Molly Grue. Together, and with the unicorn in disguise (I’ll leave this point vague to avoid spoiling the story), the trio faces the Bull and the intrigues of Haggard’s court, which for the unicorn include the unwanted affections of the king’s adopted son, Prince Lir.

So far, the novel might sound like many fantasies, and in a certain sense it is. There’s not only a unicorn, but also ogres, dragons, and a harpy. But there’s little consistency as to which fantasy elements fit within the rules of the universe and which don’t. The novel’s world is a hodgepodge of magical creatures and moments without much backstory. The land’s geography is incomplete. Readers know about the existence of the unicorn’s forest, Haggard’s castle, and a few places between those two locations, but not much else. There’s magic, to be sure, but even the wizard Schmendrick has no idea how it works and can’t control it. This is unlike popular recent fantasies that showcase complex magical systems that work according to specific rules; Patrick Rothfuss’s The Kingkiller Chronicle series and Brandon Sanderson’s Mistborn series come to mind. (Rothfuss, by the way, calls The Last Unicorn “the best book I have ever read.”) By modern standards at least, Beagle’s story is missing some essential world-building.

The Last Unicorn is also littered with anachronisms. It’s chock-full of modern-day references and colloquialisms that pull the reader right out of the invented world—a bricolage that would shock the consummate sub-creator Tolkien. Only 10 pages in, a butterfly talks about taking the A train and quotes the Bible. Molly Grue is part of a band of merry-folk living in a greenwood who know the legend of Robin Hood and speak about Francis Child, a 19th-century collector of English ballads. Schmendrick—whose name more or less means “foolish” in Yiddish—is “the last of the red-hot swamis,” which is a term for Hindu monastics. T. H. White’s 1958 retelling of Arthurian legend, The Once and Future King, also contains frequent anachronisms, but in that story Merlyn is living his life backwards through time. The Last Unicorn offers no explanation for its forays into modernity.