How does Hugo-winner Timothy Zahn turn an otherwise straightforward SF page-turner into something truly interesting? With one of the oldest shticks in the book: the good ol' black-hole-that-spits-out-quantum-particles-of-human-goodness trick. Of course, that's not exactly an old sci-fi shtick, but the essence of it (and its effect) is: the ever-clever Zahn has taken a very cool idea--what if there were quantum particles (or whatever) that compelled people to act ethically--and then explored the impact that might have, in this case on a society and its internal and external interactions. The particles in question are called "angels," and the interstellar alliance known as the Empyrean has been blessed with Angelmass, the eponymous black hole that emits them. The greedy, Earth-based Pax empire sees these angels as a brainwashing alien invasion and threatens to invade the Empyrean itself to set things straight. Thrown into the fray to explicate the implications are a bumbling but earnest Pax scientist-spy, a pretty young grifter, a brother-sister pair of grizzled space vets, and an Empyrean High Senator who fears the complacency that angels have bred into his society. Fast, fun, and thought-provoking, Angelmass combines Star Wars-style action (which Zahn knows well) with enough substance to satisfy a more serious reading. --Paul Hughes