It starts off slower than the first two installments, but this third book broadens the story's scope, answers several key questions, humanizes unlikable characters, and brings former rivals together. There's a lot going on in this last book before the fourth and final one. It's harder to get through -- with lots of new and returning characters, backstories, and allegiances for readers to sort, classify, and keep track of at first. But at about the halfway point, the pieces come together, and the action takes off to where it's once again difficult to stop reading. The Blood Shrike in particular steals the show in this installment. She's stuck serving the Emperor now that her beloved younger sister is Empress, and that forces her to do a few seemingly unforgivable things to Laia and Elias. But as the story unfolds, it's clear that the Blood Shrike, with the help of the clever, loyal, and steadfast Harper (who unbeknownst to Elias is his half-brother), begins to realize, like Laia, that the Nightbringer is a threat not only to the Empire but to all of humanity.
Laia continues to grow as a character -- honing her leadership skills and following her instincts now that Elias isn't by her side at every moment. Shippers will delight in one romantic scene between Laia and Elias, but otherwise Tahir keeps the two apart as they separately deal with practical and supernatural challenges. It's actually the obvious feelings between Helene and Harper that are most rewarding, since they're both bound to put duty over personal desire. Surprisingly, Elias' story is probably the least interesting this time around, but his new position as Soul Catcher in training (and his difficulty fulfilling that responsibility) plays a significant role in this installment's climactic events. Give this one time to build and it will reward you with some epic battle sequences and alliances that are sure to eventually defeat the big bad villain in the final book.