Ace #24620, 1973. Although this title starts with "Forerunner" it is actually the 3rd book in the "Warlock" series (which is the 3rd part of the Forerunner Series).

Includes Preface written by the author.

When a highly skilled sensitive, or mind reader, comes into contact with a strange green stone, she finds herself trapped in the past in the identity of another person.

Only Andre Norton could have created Ziantha, and the story of how her powerful mental talents led her to the eerie stone of power that drew her on a deadly quest, back through ancient empires and alien reincarnations, seeking the lost talisman of a forgotten race. Forerunner Foray is a vivid window on the future that no science fiction fan can afford to miss!