Planescape: Blood Wars, Book 01 - Blood Hostages

Aereas knew nothing about the planes and the evil denizens that dwelt there... until his uncle was abducted by a pair of gargoyles in the employ of an eight-armed god. Hot on the trail of these otherworldly kidnappers, Aereas and his cousin, Nina, enter bizarre and twisted worlds beyond imagining. Aereas finds that his uncle’s abduction is part of a much larger plot to turn the tide of the fiendish Blood War and loose an unspeakable evil throughout the planes. Though the planes hold unspeakable evil, they also hold unimaginable good—the two in a delicate balance. The only question is: Which way will Aereas and Nina tip the scales?