Perhaps the most vivid and memorable passage in the whole of The Hobbit is the chapter "Riddles in the Dark," in which Bilbo Baggins encounters Gollum in a cave under the Misty Mountains and enters a riddle-contest with him in which the prize is his own life. It is memorable for a number of reasons: the intense and creepy atmosphere of the cave, the stark contrast between the comfortably civilized Bilbo and the feral and insane Gollum (who are nonetheless the same kind of creature), the constantly rising tension as each riddle is asked and answered, making it more and more likely that Bilbo will fail and be left at Gollum's mercy. The riddles themselves are less obviously important, except for the last one, "What have I got in my pocket?", which is barely a riddle at all. Gollum himself dismisses one of Bilbo's riddles contemptuously with a cry of "Chestnuts, chestnuts!", implying that Bilbo has not made up a fresh riddle but is recycling a very old and familiar one. It would be in keeping with J. R. R. Tolkien's methods and his preferences if all the riddles were old, and part of the task Adam Roberts has set himself in The Riddles of The Hobbit is to investigate the riddles and trace their antecedents and origins in the Anglo-Saxon literature with which Tolkien was so familiar. But that alone would make for a thin and rather excessively specialized book, and Roberts has a bigger project in mind.

Despite the book's title, Roberts does not limit his scope to The Hobbit, instead using that novel's riddle-game as a jumping-off point for an examination of the role and nature of riddles in all of Tolkien's work—including The Lord of the Rings, The Silmarillion, and even such posthumous works as The Children of Húrin—and finding riddles and riddling in more places than one might suspect. As it turns out, riddles and riddling were everywhere in Anglo-Saxon literature, which Roberts demonstrates with extensive quotations and descriptions. The riddle-game that Bilbo and Gollum play was not invented by Tolkien, but was a staple both of poetry and of life for the Anglo-Saxons. For a warrior to be able to boast of his great deeds with wit and cleverness was almost as important as being able to perform the deeds in the first place, and a familiarity with riddles (in particular the kind of riddling poetic metaphor known as a kenning) was a vital component of such wit. But beyond even this, Roberts argues that, far from being mere games or decorative tropes with which to embroider a story, riddles fundamentally informed and shaped the view of life and the cosmos held by the Anglo-Saxons:

Riddles are more than mere pastimes; they speak to the puzzling circumstances in which we find ourselves . . . The Anglo-Saxon view of life is that it is a riddle not because it can be in some sense "solved", but because there is an ironic relationship between what is presented and what is meant—between what is to-hand and how things really are. "Riddling" is the best way to apprehend this irony, because the mismatch is something to be encountered playfully, joyfully, not surlily or resentfully (p. 19, 23)

The relevance of this deeper form of riddling to Tolkien's work may not be immediately obvious, but making these kinds of connections is part of the larger task that Roberts has set himself. One crucial key is what Tolkien described in his lecture on Beowulf as "the theory of courage." This is the belief, taken directly from Anglo-Saxon and Norse literature and mythology, that "victory or defeat have nothing to do with right and wrong, and that even if the universe is controlled beyond redemption by hostile and evil forces, that is not enough to make a hero change sides" (Tom Shippey, J. R. R. Tolkien: Author of the Century, p. 150). The hero's defeat, in other words, doesn't prove him wrong. This theme underpins most of Tolkien's work to a lesser or greater degree. As Roberts puts it, "'What is a defeat that is not a refutation?' takes the form of a riddle, and it has more than one answer" (p. 24).

Roberts stretches his argument a little in chapter 4, "The Riddles of the All-Wise," when he attempts to make a direct connection between the riddles exchanged by Bilbo and Gollum and a section of the Norse Elder Edda known as Alvissmal, or "riddles of the All-Wise." It's certainly true that if we posit that Tolkien embedded an acrostic meta-riddle in the answers to the riddles, and if we grant that the the meta-riddle doesn't include the answer to Bilbo's final question "What have I got in my pockets?", and if we take each of the riddles' answers to have a corresponding letter or rune which is not necessarily the first letter of the answer in English but is somehow symbolic of the meaning of the answer (so that "fish," for example, is represented by "S" because an S has the sinuous shape of a fish moving through water), then it is possible to use the answers to the riddles to spell out ALVISSMAL; but firstly, that's a lot of "if"s, and secondly, it's not clear that all of this speculation leads to anywhere useful or interesting. It feels, frankly, rather like a solution in search of a problem, or an answer to a question that nobody asked. There is surely no need to construct such a tall and precarious house of cards in order to point out that the Alvissmal exists, and that Tolkien was familiar with it, and that it offers antecedents and origins for the riddle-game and for the earlier incident of the trolls turning to stone when the sun rises.

But perhaps this is missing the point. Roberts may not have conclusively proven that there really "is" an acrostic embedded in Bilbo and Gollum's riddle-game, but in digging out the outlines of one in the manner of an archaeologist excavating a building, he is engaging in a game of reverse-riddling of the kind he recounts from the Alvissmal, demonstrating his thesis by example; just as an Anglo-Saxon warrior might boast of feats of arms, he, as a modern critic, is showing off his skill at close-reading and interpretation and the depth and breadth of his learning in a display that may not be convincing, but is certainly dazzling. Indeed, none of the charm of this book depends on a sense that the answers proposed are "correct" in some definitive sense, for, as Roberts repeatedly stresses, a riddle need not have a single correct answer, and the kinds of riddle posed by a work of fiction as rich as those written by Tolkien are not likely to be exhausted by a single solution. Rather than finding correct answers, or even looking for them, Roberts offers a sense that this riddling mode of reading gives us a new way of seeing Tolkien's work, and shows off a sprightly and acerbic wit in deploying it.

As a result, even when it is not entirely persuasive, the book is enormous fun to read, whether Roberts is imagining Oedipus nitpicking the Sphinx's solution to her riddle ("Metaphorical legs! Not literal legs! Legs in a man-ner of speak-ing!" [p. 53]), or noting parenthetically of the ninth-century Leechbook of Bald: "and what a superb name for a medical textbook that is" (p. 59), or, in a more serious mode, contrasting the ways in which fantasy and naturalistic fiction engage with reality ("I daresay many of the rank and file soldiers in the orc army come from broken homes, and had little opportunity for advancement except joining the military" [p. 156]).

Underpinning the wit, Roberts has a degree of imaginative sympathy with Tolkien that is rare, even among his admirers. This can be seen most clearly in his treatment of Tolkien's religious beliefs. It is refreshing to see a critic who does not share Tolkien's faith but is still willing to take it seriously. There can be no doubt that Tolkien's Catholic beliefs informed and animated much of his fiction, even those aspects with a distinctly pre-Christian flavor; for all that he took inspiration from Norse and Old English pagan myths, he looked at those myths with Catholic eyes, which Roberts understands and uses as a basis for deeper insights. Most notably, in pondering the form of the One Ring, Roberts asks: why is it a plain band of gold, unlike the other Rings of Power, which are all adorned with gems? Why, in other words, does it look exactly like a wedding ring? The answer Roberts proposes is ingenious, and is rooted in Catholic theology in a way that makes perfect sense and provides a fruitful new perspective on the symbolism and meaning of the One Ring.

The Riddles of the Hobbit is that rare thing: a work of literary criticism which is both erudite and entertaining, both well-grounded in close reading and research and immediately accessible to all readers. In his introduction, Roberts says "I take it that a mode that prizes invention and ingenuity is best discussed ingeniously" (p. 15), and he has lived up to his own standard. Witty, clever, thoughtful, and fresh, The Riddles of The Hobbit is a treasure.

Katherine Farmar is a writer based in Dublin, Ireland. She blogs about the arts at Pansies and Nettles.