The last druid / Terry Brooks.

"Bringing a conclusion to an epic that has spanned centuries is a vast undertaking, but Terry Brooks is entirely equal to the challenge... As the Four Lands reels under a brutal invasion from across the sea, spearheaded by a nation determined to make this land their own, our heroes must decide what they will risk to save the integrity of their home. For as one group remains to defend their homeland, another undertakes a perilous journey across the sea to the homeland of the invaders, carrying with them a new piece of technology that could change the face of the world forever.For both groups, the stakes could not be higher. For those who remain, one of their key allies has been banished to the Forbidding: a demon-filled prison from which there is no escape. And the one who sent him there now stalks the land with a fearsome demon at her side, determined to seize what power she can. While across the sea, a small band of heroes has been shipwrecked far from the land they seek. Can a young girl free her mentor in time to stop an invasion? And can a strange new science reach a foreign shore in time to alter the fate of two nations...providing the device even works?"--Publisher description.