The Shard of Time — Clifford B. Bowyer

The Mage's Academy is like no other school in the Seven Kingdoms. Just when Kyria thought that she knew what to expect, she learns of the Shard of Time, a mystical artifact that has the power to send people back in time and experience events as they actually unfolded. Determined to learn more about Zoldex, the foe that she is destined to defeat in the Madrew prophecy, Kyria and her newfound friends, Mica and Sartir, will risk everything to acquire the Shard and use it to go back in time.