The Young King — Doug Wilson

Peter and Siobhan are transported by the sea division of the Time Road back to England, where the Romans had just departed and the Saxons are in control. That was where Merilyn has been scoping a local town, which is heavily controlled by the evil Saxons. He still has to find the book of necromancy, which has the final spells needed to defeat the Miasma. In an astonishing turnaround, the hilt of a large sword appears mysteriously and is fixed in the wall of a small chapel. The wizard announces that great power will come to anyone who can remove the sword. The chief of the Saxons failed miserably, but Peter easily removes the sword, which turns out to be his own, from the time he fought the Vikings. The Saxons had built a great army at their castle, and representatives of the evil Miasma were helping. Siobhan meets an attractive French knight, who has agreed to help their battle. Peter falls for a striking young witch, and her family also agree to join the battle. A Roman legion is resurrected, and the battle commences, with magic and fear abounding. The Saxons are defeated. But the Dark Lord, the true head of the evil Miasma, is determined to destroy Peter, who is now recognized as the rightful king of England and the inheritor of the crown of Arthur. This battle is far more dangerous than the one for Saxon castle. Toward the end of the book, the necromancy appears, so Merlyn can bring his full powers to bear on the final onslaught. But there is a terrible price to pay. Even Merilyn does not want to go there. But there's no choice.