In a retro-future world, the Earth has been reduced to a ruined wasteland after 1,000 years of war between Heaven and Earth. The war began ten years after our present time, when human medical scientists pushed over the boundary between life and death, resuscitated a human brain, discovered the reality of an afterlife in Heaven and ended up in a war against the angels. Now, Earth’s military forces are composed of artificially created Humen, and the original human beings have been reduced to a mere survival existence, living in fearful, isolated tribes. The trilogy begins when Miriael, the Fourteenth Angel of Observance, is shot down and crashes to Earth. A young tribesman called Ferren finds her lying in the grass, damaged and unable to fly. She ought to be his enemy, since his tribe consider themselves allies of the Human, but curiosity and pity outweigh the rules of his upbringing. In Ferren and the Invaders of Heaven, the climactic book of the trilogy, the Humen launch their long-awaited invasion of Heaven. Their armies have devised a way to scale the sky—and the battle to end all battles is about to begin. They also have a new leader—the most deadly kind of enemy for the angels, because he’s a twice-fallen angel who knows all their secrets. In the end, Ferren and his fellow Residuals will have to pick a side. But before they can join the fighting, they’ll need to sort out the fighting among themselves. Ferren will also have to sort out his love-life between Zonda and Kiet, while Miriael still has unfinished business with the beautiful angel she once fell in love with … The setting draws on the traditional Judaic/Christian/Islamic lore of angelology, although this is not a religious book and carries no hidden religious message.