Kenneth Oppel gives a bat's-eye view of the horrors of animal testing in Sunwing, the sequel to his popular and award-winning novel for middle readers, Silverwing. Shade, the lost baby bat of the first book, has rejoined his colony only to lose his freedom as the bats plunge into a mysterious human building they believe is paradise. The building's vast interior forest, with its teeming insects and eerie absence of owls, certainly seems like Eden. But Shade and his Brightwing friend Marina, now young adults, discover that the humans have a sinister motive for befriending the bats--they are using them as unwitting suicide bombers over a jungle war zone. In addition, the bats are threatened once again by Goth, the giant jungle bat with the cannibalistic tastes and irrepressible knack for survival of Hannibal Lecter. This time he has a plan for making his god, Zotz, supreme: to be explicit (and Oppel is), by ripping out the hearts of 100 imprisoned bats, owls, and rats. Shade's and Marina's race to save their companions from this two-pronged threat makes for exciting and occasionally terrifying reading.        Once again Oppel immerses readers in the world view of his tiny flying mammals. It becomes second nature to see things upside down, hide in crevices, squint at the brightness of the sun, and sense danger through sound vibrations. Particularly chilling is his portrayal of the humans' laboratory, with its concentration-camp-like indifference to life. In Sunwing, Oppel offers breathless suspense while eliciting our compassion for these misunderstood creatures of the night. (Ages 9 to 12) --Lisa Alward