I have always felt that one of the nicest things a friend can do is give me book recommendations and reflect with me on how those recommendations went afterwards. Happily, there’s no reason a friend has to be real to do it. Some books refer to one other book, or two—but books about bibliophiles are treasure troves. Very few readers of Roald Dahl’s Matilda are ready to plow through Great Expectations—but when they do, they might remember her with a smile. While the education of Frankenstein’s monster is an unlikely source for a reading list, there’s no reason an avid fan of the book couldn’t read Plutarch, Milton, and The Sorrows of Young Werther to experience what the creature did alongside him.

My own book club friends didn’t start with Matilda or the Creature. While I have a habit of noting titles and pursuing them, my first really serious imaginary book club experience was born of necessity—the necessity of needing reading material from a college library. The Library of Congress system is useful for organizing large amounts of nonfiction, but there’s a reason most public libraries don’t use it for their collections: author nationality and year of first publication is not how most of us browse. One January term brought me a course in FORTRAN: stultifying from a reading perspective. I needed books, and I needed to know what I was looking for going in. My eye fell on Pamela Dean’s Tam Lin, and a plan hatched fully formed: the gently fantastical college setting of this ballad retelling makes it a perfect source of reading material. Janet reads a very large number of things, and I hadn’t gotten to nearly all of them. Even the introduction was full of suggestions: Sylvia Townsend Warner, Gabriel García Márquez for heaven’s sake! By the time I got to college I knew Tam Lin nearly by heart, but I didn’t know all the depths of it because I didn’t know all the references.

I can’t read the books on Gandalf’s shelves. I can’t drink from the waters of Lothlórien. But I can find out what on earth A Tan and Sandy Silence is and what it means that Janet, an English major, brings it along to college and reads it alongside the things I knew (A Wind in the Willows, A Wrinkle in Time) and the things I knew I was supposed to know (Keats, Coleridge). (It’s a mystery novel by John D. MacDonald, and it was one of the few things my college library could not supply from Janet’s reading list—and, combined with being #13 in its series, that meant that it took me the longest to read. Only to find out that the main insight was: Janet read new mystery novels. I didn’t say that every insight in this exercise was a deep one.)

I wasn’t meant to know every reference, of course—that’s not what novels about bibliophiles are for. The books Tam Lin’s Janet reads in her classes are frequently related to the plot and the theme; the ones she brings with her to college are sheer characterization. Knowing that she prefers Sayers to Christie gives you a piece of Janet; knowing that her roommate Tina is the opposite, and how Janet reacts to that, is a little piece of their prickly budding friendship in a nutshell. When I first read Tam Lin I knew that the character of Molly was open-minded and compulsively bookish because she was willing to pick up her new roommate’s copy of Magister Ludi and give it a try even though she had previously not liked Hermann Hesse’s work, even though she was scowling at it. After that desperate time collecting Janet’s reading material from the college library, I knew that I would scowl along with her.

The truly necessary plot points for Janet’s college reading go into the text—what the characters think of Hamlet fall in right alongside Hamlet. It’s perfectly possible to understand Tam Lin without ever having read or seen Hamlet. But going back and forth between the two gives a doubling effect—the next time I watched Hamlet, Janet’s production was in my head, Robin’s opinion of the antic disposition, the parts that most affected Thomas. The Hamlet of Tam Lin is with me for all my other Hamlets—for the Hamlet of Isabella Hammad’s Enter Ghost and Victoria Goddard’s Till Human Voices Wake Us and all the rest—and those Hamlets return with me when I return to Tam Lin, with the character of Janet over my shoulder as I see it done by magicians or in the West Bank.

Another set of book club mirrors came from Jo Walton’s Among Others, which itself, delightfully, contains a book club. Among Others may be a fantasy about subtle magic in the changing landscape of England and Wales, but it is even more about the changing landscape of its heroine’s psychology—and as an avid reader, books are crucial to how she thinks about both kinds of landscape. One of its central texts, both at the midpoint of the book and at its emotional core, is Ursula K. Le Guin’s The Lathe of Heaven, and when I first read Among Others, it was in a weird intermediate ground for me: read but not well remembered. So when Mori says that it’s “the perfect book for this” and “It’s better to be like George Orr than have her win,” I had only the dimmest recollection of what that meant. I knew that George Orr was the central character of The Lathe of Heaven, and the rest of the scene in Among Others illuminated what Mori was wrestling with well enough that I wasn’t completely lost in that book.

Then I returned to The Lathe of Heaven and to Among Others after it, and the shadowy sketch sprang into full color. George Orr’s grasping for the uses of inaction in a world that fetishizes action is perfect, and is almost certainly the first time Mori Phelps, steeped in the square-jawed heroes of Heinlein, has encountered anything similar. While the comment that it’s the perfect book is in Mori’s voice, it is the perfect book for the discussion Mori wants to have—I immediately wanted to sit down and be the adult to have it with her. All the themes of power and its uses are right there, and she is absolutely right to yearn for someone who can help her have that conversation—and absolutely right to be glad that Ursula K. Le Guin was that person in paper form.

I hadn’t read Mary Renault or Nevil Shute when I read Among Others, and I did go find them after, and that was lovely, bouncing back to look again what Mori had said about the different volumes and what I thought about them—but it also made me notice that there is another reflection of this same thing as Mori says, “I’m not sure I really like The Number of the Beast. There’s a lot to like about it, but it’s all over the place as far as plot goes, and as far as location goes as well. I’ve never read Oz or the Lensmen, and I’m not quite sure what they were doing there.” I have read Oz and the Lensmen, and I see what Mori not having read them is doing there—among other things it is marking her place and time as clearly as her attitudes and vocabulary. She doesn’t know about Oz where an American of her age would, just as she doesn’t know what modern attitudes toward some of her father’s parenting would be—it’s part of what makes her this specific character in this specific setting, an inverse illumination. And it’s not the same as reading with Janet from Tam Lin would be—Janet explicitly recognizes the Patchwork Girl of Oz when one of her dorm mates uses her as a Halloween costume. Imaginary friends make a great book club but not identical members of that book club.

Sadly, imaginary friend book clubs are not universally delightful. After my success with Tam Lin, I was in another Library of Congress-limited situation and remembered that the characters in Madeleine L’Engle novels read all sorts of things. I learned about both Robert Frost and John Donne (together again for the first time, one might have thought, were it not for every introductory English verse anthology ever), and that went pretty well—surely the adoration the L’Engle characters all felt for the plays of Anton Chekhov would be an utter treat in my life! I saved them for a particularly lonely summer of physics research, relieved only by frequent trips to the university library. The insight I got was: Madeleine L’Engle spent a lot of time in theatre productions of The Cherry Orchard as a young woman and absolutely thought it was the bee’s knees, and she did not apply this at all discriminately in places where it made any sense to her characters or what they were going through; she just really liked it. People are allowed to like things, but sometimes the literature characters are given to like doesn’t actually illuminate the plot, the setting, or their character; sometimes it’s more or less random, the author’s taste put in the book, and the more consistently it shows up acting like it might mean something, the more disappointing that experience later is.

Not all bibliophile reads ever promise more. Puns like the character name Millon de Floss in Jasper Fforde’s Thursday Next books, for example, are never intended to signal that reading The Mill on the Floss will give you greater insight. I’ve done it. It doesn’t. But I never thought it would; the only pleasure signaled and the only pleasure gained—a contract with the reader thoroughly fulfilled—is that of recognition. This is not a pleasure to be denigrated.

Every reader’s imaginary friend book club experience will be different. Some readers will nod sagely when Gentian in Pamela Dean’s Juniper, Gentian, and Rosemary stands perfectly still at the title of Growing Up Weightless; others, like me, will stand still themselves—and then rush out and get the book, and find out why her father says the friend group is like Gentian’s own friend group. Some readers will come upon Diana Wynne Jones’s Fire and Hemlock early enough to grow up with Polly as she reads Tom Lynn’s gifts (what is it with bibliophile Tam Lin retellings anyway?)—and others, like myself, will be grown-ups who have already read them by the time they got there. Karen Joy Fowler’s The Jane Austen Book Club is a title that appeals substantially to people who have already read the works of Jane Austen, but the mirroring effect can still give further insights bouncing back and forth and back again.

I keep noticing new bibliophile books on the shelves, books with “library” and “bookshop” that I haven’t had the chance to read, with the potential to let me read over the shoulder of new characters. I love the chance to have that kind of insight bounce back and forth between the texts, the real and the magical illuminating each other endlessly.