This review was difficult to write! I had to take some time to piece my thoughts together after finishing Howling Dark, and honestly I'm still not sure if I've completely decided how I feel. Ultimately, I think determining the strength of a sequel can be answered by asking: "does this story deliver on the promises of the original?" And while there is much to like about Howling Dark (and some stuff to like, uh, less), I'm not convinced it does.I LOVED Empire of Silence. I adored the dazzling, far-flung future world it created, and all the carefully crafted empires and societies and cultures it introduced. The blend of military sci-fi and fantasy was fascinating, and the omniscient narrator teasing out how the story would conclude (while still maintaining a level of suspense) made it really unique. Hadrian was a bit of a bland main character, but certainly not objectionable, and anyway, there were dozens of colorful and intriguing side characters to balance him out. However, in many ways, Empire of Silence was a long (800 pages!) introduction to the Sun Eater saga, rather then a story in and of itself. It was in some ways, a long, glorified prologue. Which is not to say that things didn't happen! There was a lot going on in that book, but once I got to the end where Had and his friends went off to find Vorgossos I realized that the whole story had just been a lead-up to the beginning of a greater, grander story the author was going to tell. Which is 100% understandable in the first book of a series, especially one so tightly packed with world-building and political machinations. I was eager for the second book to take over and fully push us into the story of Hadrian Marlowe. And it...kind of does? In some ways? But when I finished Howling Dark I had this irritated moment of deja vu...because in many ways Howling Dark does the same thing Empire of Silence does. It ALSO feels like the beginning to a larger, grander story. And you can't really do that more then once!At almost 700 pages, Howling Dark didn't really have an excuse for being as empty on plot as it was. It was an engaging read for sure, and yes ~things happened~ but the plot can actually be boiled down to a sentence or two. Hadrian finds Vorgossos, and fails miserably at diplomacy (several times!). There's some interesting, if confusing, stuff going on with the Quiet, the Mericanii machines, this organism called the Deep, and the web of connections and unclear allegiances that link them all together. The stuff with the Quiet kind of exemplifies how I feel about Howling Dark as a whole: it's really interesting, but unnecessarily drawn out, and ends up feeling like a teaser for something more that'll happen...eventually. I get the sense that this author wants to make this series into a sprawling, long saga, but it ends up feeling like he's plugging filler in order to do so.I don't want to get too down on this book. It did have a lot going for it, Hadrian ends up sharpening into a more distinct, and memorable character - and you finally get the sense why he's reviled as a monster, since he does some genuinely monstrous things for believable reasons in this book. It's rare that authors push their characters into morally reprehensible territory (unless they're a cliched anti-hero or grimdark "protagonist" from the get-go), so it was refreshing to see Hadrian's "who you are in the dark" moments. He also doesn't shy away from making sure there are real and tangible consequences for Hadrian's actions, and isn't afraid to make Had lose or injure him (physically or emotionally). This helps keep the plot grounded (important, considering the fantasy element is becoming more showcased!), and makes any "happy" or bittersweet endings feel appropriately deserved.Valka becomes more likable in this book, although the cast of secondary characters don't have as much to do. The gladiators in particular get side-lined, and while they're in the book often, they rarely have much to do. Bassander Lin is terrific as a nuanced antagonistic presence for Hadrian, and he's probably the most well-developed side character in Howling Dark. The Exalted, Kharn Sagara, the Ceilcin, and the machine gods that lurk underground are also compelling, but Howling Dark is more interesting in introducing these characters then really digging too deeply into them (Kharn Sagara being the possible exception).Ultimately, Howling Dark was a perfectly enjoyable story, but left me feeling more disappointed then excited. I don't think it succeeded at delivering a satisfying follow-up to Empire of Silence - instead, it functioned more as another prelude to the larger story that's teased at. I'll keep reading this series, but I really hope the next story turns around and actually fulfills the promises of it's predecessors.