Every now and then, a book pops up on social media that, the instant you see it, you know it must be yours. That was the case with Fairylore: A Compendium of the Fae Folk by Sara Cleto and Brittany Warman, which was touted on Facebook by author Charles de Lint (who is, after all, no slouch in the folklore department himself). A few days later, it was in my possession.

I read it ... slowly. Not because it wasn't an enjoyable read, but because it was. It is, at its heart, a reference book, and that's not the sort of book that most people just sit down and peruse without pause. (Some will, regardless, and more power to them!) So for several weeks I kept it handy. I also read some novels, some nonfiction. I did other things. And, when the urge struck, I picked it up and turned a few more pages. Sometimes, a lot of pages.

The authors explain in their introduction that "fairies and fairylike creatures are not limited to any specific time or place. They're everywhere, seducing humans or cleaning their shoes or terrorizing them in the woods under a new moon."

If fairies don't have any consistency in how they look or appear to humans, it's just as true with regard to their actions. In fact, the greatest consistency is inconsistency.

The introduction is more than 30 pages long, and it is an interesting series of essays on the nature of fairies and fairylore (a term the authors prefer to "fairy tales," since most fairy tales don't actually involve fairies). They delve into what exactly defines a fairy (the answer is somewhat nebulous) and what separates fairies from other types of supernatural beings. They note that fairies in some stories have become ghosts or witches because they fit more neatly within a particular cultural perspective. They present several theories to explain the existence of fairies, and they discuss how time seemingly moves differently in fairy realms.

And they explain why people have always told -- and continue to tell -- fairy stories. Simply enough, "we tell fairy stories to make sense of things that befall us. They are a way of making sense of our world and our experiences."

Fairy stories can be a way to explain things with no ready explanation available. Why did Uncle Fergus die so young? Because he was such a good man and such a skilled fiddle player that the fairies stole him for themselves. Why did the baker lose his sight? Well, he saw something the fairies didn't want him to see. Fairies are especially likely to show up in moments of transition or danger, and they can be harbingers or explanations of disaster. They also can be a way to feel that you're exerting control in a chaotic world. If you treat the fairies kindly, if your local magical ecosystem is balanced, then peace may be maintained and disaster avoided.

Then we get to the heart of the book: the compendium itself. While noting that most similar books on the market simply present fairies alphabetically or divide them by geographical location, Cleto and Warman have chosen instead of organize their book based on type of fairy. Chapter headings include "Fairies of the Home," "Fairies of Seduction," "Fairies of Terror," "Fairies of Nature," "Fairy Neighbors" and "Our Fairies, Ourselves."

We believe that this approach highlights why these fairies matter so much culturally. It allows us to go more in depth into each individual fairy and emphasizes the things that connect them to humanity, to us. As we've said, ultimately the most interesting thing about fairies is that they are a way for to speak about the world, their own experiences, and their own lives.

Unlike Katharine Briggs' exceptional reference book, An Encyclopedia of Fairies: Hobgoblins, Brownies, Bogies, & Other Supernatural Creatures, which is arranged in a standard encyclopedic format (and was reviewed here), Fairylore does not attempt to be all-inclusive. Cleto and Warman acknowledge that "we cannot include every fairy from every source."

(In fact, pre-ordering the book in advance of its Feb. 10 release date earned buyers two .pdf files, one including 10 fairies who were cut from the final draft for space reasons, as well as six stories that were likewise omitted. If you missed that window and want to know what you lost, here is a list of the 10 entries included: the Acalica, weather fairies from Bolivia; the Asuras from India, which first appeared in the Vedas of Hindu mythology; the Bean Nighe, the Celtic washer-by-the-ford; the Bruxa, a vampiric shapeshifting witch from Portugal; mischievous Cornish piskies from southern England; the Dayamdam, insect-like fairies from the Philippines; the Grindylow, a Celtic water spirit most famously personified by Jenny Greenteeth, who likes to drown small children; Hantu Kayu, a sort of seductive ghost from Malaysia; the Sluagh, the "unforgiven dead" of Celtic lore; and the Tunder, kind female fairies from Hungary who protect orphans.)

The chapters that do come with the book are rich in detail, written in a conversational tone that presents the text in a friendly, informal, often whimsical style.

In the pages that follow, you'll find a wide array of fairies, each described briefly. A random sampling includes the Dullahan of Ireland, the Kappa of Japan, the Saci Perere of Brazil, the Tamawo of the Philippines, Brownies and Boggarts from the United Kingdom, the Ifrit of Islamic cultures, the Yaksha of India, the Abatwa of Southern Africa, the Gwragedd Annwn of Wales, the Good Folk of Canada, the Menehune of Hawaii, the Kelpies of Scotland, the Veli of Fiji, the Alux of Mexico, the Leannan Sidhe of Ireland and the Isle of Man, the Bakru of Suriname and Guyana, and Fox Spirits of Japan, China, Korea and Vietnam. Each section also ends with an illustrative story about one of the featured fey.

Some entries are more useful than others. Consider this entry for the Nix.

The nix is a truly spectacular case study of why fairy categorization is always an exercise in futility. It goes by a number of names, including but not limited to nixie, nixy, nix, nankeen, nicor, nokk, and nokken across German and Scandinavian regions. We considered folding it in with kelpies because it's often regarded as another water horse, but also it's often described as half human and half fish. And as a generalized shapeshifter. And as a wyrm or a dragon. And as a Germanic melusine. And as a Germanic rusalka. Sometimes, nix are described as exclusively male ... and sometimes as exclusively female. They can seduce and repel and eat humans and marry them and drown them -- in no particular order. They are usually malevolent, but they also love music and art and dancing, and can be bought off with gifts. They might appear as a strapping man, an old woman, or a fair maiden. We could have put this fairy almost anywhere in this book and made a case for it.

Well, that's not very helpful, is it? Still, I can honestly say most entries provide far more definitive descriptions.

The book is richly illustrated, with cover and interior paintings by Annie Stegg Gerard, and less detailed but no less evocative fairy sketches scattered throughout the text by Kristin Kwan. The illustrations definitely add an extra dimension to the book, which is solid and hefty and feels good in one's hand while reading.

For readers who fear that fairies, if ever they existed, are now gone from this world, rest easy! Cleto and Warman end with hopeful words.

The fairies are always vanishing but never truly gone: Rumors of the demise of the fairies have been greatly exaggerated! The fairies are still here -- they're in our stories in our music and our pop culture. They're in our landscapes, in the trees we won't cut and the rocks we won't move. They're in us, when we dress up for a fairy festival or even just put on some sparkling wing earrings to run to the grocery store. Fairies are remarkably resilient ... and we're pretty sure they're going to be around for a long time yet.

Optimistic, indeed. I hope they're right about that. And, if they are, and if you see one, this book could help you identify exactly what you're seeing! (Although, let's be honest, you should probably pick up a copy of Briggs' An Encyclopedia of Fairies, too, if you can find one.) In any case, Fairylore is a good resource, and a pleasant and informative reading experience.