The Crystal Heart — Sophie Masson

A girl in a tower. An underground kingdom. This retelling of Rapunzel offers a gripping blend of magic, romance, adventure, fairytale, and mystery.

When 17-year-old army conscript Kasper Bator is chosen to join the elite guard that keeps watch over a dangerous prisoner in a tower, he believes what he's been told: the prisoner is a powerful witch. But when he meets the prisoner, Kasper's life will change forever -- for the prisoner is no witch, but a beautiful young girl. The daughter of the country's enemy, the Prince of Night, Izolda has been held hostage since she was three. And she is in imminent danger, for a prophecy says she must die on her 16th birthday if Krainos is to be saved from the Prince of Night. Kasper decides to help her escape. As the days pass, their friendship turns into real love, but their hiding place won't stay safe forever.