Tina Talinka and the Echo of the Allohom (Tina Talinka's Adventures Book 2)

A cryptic cry for help leads Tina from London to an archeological dig in France. Here, she learns she must stop a Medieval Tyrant and to save a group of Cave Monsters. To do this she must use her powers of Time Travel and rely on the help of a new friend who takes the form of an old enemy.