It wasn't that this was a horrible installment of the "How to Train Your Dragon" novel series. However, it lacked much of the luster that has characterized many of the other books. In a typical novel, I expect to laugh over crude and silly humor, go on a high stakes adventure, and watch Hiccup magically pull out tricks to save himself in the nick of time. In all these areas, though, "A Hero's Guide to Deadly Dragons" does not fully deliver.
The Downsides
The humor was present but not quite as flamboyant as some of the other books were. The entire setting of kids going through a spooky library does not provide quite as much material by which to joke, nor were their hazards so ridiculous that their adventures could spice up the comic relief, either. All in all, while the book was amusing and had its cheeky moments, it didn't shine.
Secondly, the idea of Hiccup, Fishlegs, and Camicazi going in to steal a book from a library on Hiccup's third/twelfth birthday feels a lot less dramatic of an adventure than what Hiccup has already endured. We can talk all we want about the fact that the Hairy Scary Librarian is a good swordsman, but when you come down to it, this adventure really lacks the flare that we've before seen.
For let's do a tally. Hiccup faced the Green Death and almost got swallowed whole in "How to Train Your Dragon"; goes on a treasure hunt, sinks the bottom of the sea after diving off a burning ship, and faces numerous dangerous dragons in "How to be a Pirate"; is kidnapped by Romans and forced to be a gladiator-like figures fighting Sharkworms in "How to Speak Dragonese"; gets chased and captured by Hysterics and almost dies from Venomous Vorpent poison in "How to Cheat a Dragon's Curse"; and has to save the entire archipelago from destruction by hurling a stone into an activating volcano in "How to Twist a Dragon's Tale."
Amidst so much drama, of near-death escapes, kidnapping, facing terrible mountain-sized dragons, diving off burning ships, and saving the world from total disaster, it almost seems like "A Hero's Guide to Deadly Dragons" is a joke plot. Right after Hiccup surfs on the Windfinder down lava, we're expected to be content with he and his friends stealing a book just to maintain Stoick's pride during a burgling competition? The premise of the quest is simply for the boys to make up for Toothless's wood eating frenzy and for Stoick to not feel so horribly beat by Big-Boobied Bertha. It's really not all that satisfying.
Sure, with the insertion of Madguts the Murderous and Gumboil, we have some more "true danger" in the storyline. But that was very much a side-element of a book which mainly concentrated on the kids wandering around a library and fighting one old man who wielded dual swords.
Not only is the adventure itself slightly more lacking than average, but it's shorter, too. Whereas the average book thus far for this series is notably over 200 pages of story material, "A Hero's Guide to Deadly Dragons" hands us only 177, and is only as thick as the other books due to its lengthy appendix. I would also think that there are more (and larger) illustrations, further reducing page size. This book took me one short day to read, whereas the others I remember spending more time.
And if I want to get nit-picky I can add another criticism that we have a continuity error - Fishlegs owns a book about visiting Rome for the first time and it's no big of a deal (reread "How to Twist a Dragon's Tale"), but here any reading at all is forbidden. It's not an enormous continuity error, but still slightly annoying for those who like in-universe cohesion.
The Bright Sides
Criticism done, I am going to point out that there is, of course, much still to enjoy about this novel. And I did, and the novel still deserves three stars. The comments I will make might be slightly spoiler-ish being as they don't happen at the beginning of the book (so you have been warned).
The first thing that was special about this installation in the series was Stormfly's introduction. We meet the little Mood Dragon in this novel, and she is a wonderful character addition from the first page she appears. A pathological liar whose color-changing gives her away makes for an amusing, selfish dragon. She's certainly a dragon I want to see more of in the next books - and I'm sure we will!
Secondly, there is something incredibly special and heartwarming to see Hiccup locate a book from his ancestor. Ever since the first book where he was introduced as Hiccup Horrendous Haddock the Third, I have wanted to know precisely what the First and Second Hiccups were like. Finding a key element of his past about which he never knew is a special reveal to both our character on his birthday and to readers.
Final Word
Keep reading. There's always going to be one or two books in a series that don't shine quite as much as the others. Hopefully this is the only one and we're back to more drama, more side-splitting humor, more high-stakes, and more pages of awesome with the following installments.