After reading "Heroes Die," I was very glad to learn that Stover was writing a sequel. Stover is amazingly good at using the conventions of action, fantasy, and dystopian science fiction while also subtly twisting them in service of his all too believable and recognizable characters. Unlike many authors, he understands that actions have consequences, not all conflicts have good solutions, and nobody can be a hero all the time. He writes great fight scenes, too.
"Blade of Tyshalle" is, in some ways, very similar to "Heroes Die." It focuses on Hari Michaelson, and his alter-ego, Caine, as he fights against impossible odds to save his family from threats on both Earth and Overworld. It includes action, dungeons, desperate last stands, and so on. However, this book spends a lot more time on other characters, including Shanna/Pallas Ril, Hari's wife; Ma'elKoth, who goes by Tan'elKoth for much of the book; Raithe, a young Monastic dedicated to killing Caine; Kollberg, Hari's old nemesis, raised up from his exile to the Labor Pool; and Kris/Deliann, the Changeling Prince of the elves. Also, Earth has become more directly involved with Overworld, to the point of creating an enclave of technology, and later releasing an incurable virus to justify an armed invasion, in the name of "restoring order;" this changes the rules of the game.
The plot is even more intricate than in "Heroes Die," but the story also contains much more social commentary and philosophy. There are many brief, odd, semi-mythic interchapters, which, once you figure out which character corresponds to which mythic figure, provide a handy road map for the rest of the book.
After I finished "Blade of Tyshalle," I wasn't quite sure what I thought of it. I let it sink in for a few days, then reread the book. I knew I liked the action and the characters, and the way the loose ends from the first book, particularly the much-vaunted "black flow" were finally resolved, but I wasn't sure about the philosophy and social theory, or about the balance among the various elements of the book.
I think, finally, that "Blade of Tyshalle" is a very, very good book. It is also, unquestionably, a flawed book, from which several plot and character complications -- and fifty to a hundred pages -- could profitably have been trimmed. But it made me think, it involved me emotionally, it convinced me it was worth the money I paid for it, and it hooked me enough that I have already reread it three times. I definitely recommend both the book, and Stover.
Just make sure you have an open mind, and a strong stomach.