Zatherra is the fourth of six novels in which Zeo finds Psuke dead. With no where left to turn, she takes to the sky in search of the fabled city, Zatherra, hoping to find the Elixir of Life. During her empyrean endeavors, she finds strange and mystifying secrets lurking high up in the aether. Upon their revelation, she is lead to the legendary city in the Clouds, but what she discovers within might just destroy all she once knew.