The Magic Manuscript: The Nine Companions — Barbara Burgess

Four friends are inexplicably catapulted back in time--but to different places and different eras. In New France, Lance and Bronwen learn of the legend of a silver amulet buried by a  well on an island in the Saint Lawrence River. Jennifer and Arthur find themselves in ancient Sumer over five thousand years ago--and in trouble. Kidnapped by Sheik Faizi, they discover their only hope of escape is to steal his golden amulet. The two amulets are somehow connected, but how? Can any of the companions deliver them to the beautiful and powerful Lady Eve on the island of Eve Ilion? And if they succeed, will they be able to return home?