Complex sentence: The second book, "Song of the Wanderer", follows Cara's return to Earth to fetch her grandmother; in seeking whom she encounters Beloved, a diabolical ancestress of hers, who is determined to enter Luster and destroy the unicorns.
Split into simpler sentences: The second book, "Song of the Wanderer", is about Cara's journey back to Earth to fetch her grandmother back to Luster. Upon arriving back on Earth, she encounters Beloved, a diabolical ancestress of hers, who is determined to enter Luster and destroy the unicorns.