<p>The messages from the Riprap man change. Instead of warning of deaths, they warn of earthquakes.</p><p>Nothing holds the Riprap man back from his true element: Earth.</p><p>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?</p><p>'Circle of Earth' - the fourth and last book in The Witch&#39;s Progress series - brings enemies and friends together, but at what cost?</p><p>Be sure to read all the books in The Witch&#39;s Progress, starting with 'Circle of Air.'&nbsp;</p>