The messages from the Riprap man change. Instead of warning of deaths, they warn of earthquakes. Nothing holds the Riprap man back from his true element: Earth. Can Portland survive even a little earthquake? How can Tara stop him? Can she bring together an alliance of witches and community members strong enough to defeat the earth spirit? "Circle of Earth" - the fourth and last book in The Witch's Progress series - brings enemies and friends together, but at what cost? Be sure to read all the books in The Witch's Progress, starting with "Circle of Air."