Skandar Smith has achieved his dream: to train as a unicorn rider. But as Skandar and his friends enter their second year at the Eyrie, a new threat arises. Immortal wild unicorns are somehow being killed, a prophecy warns of terrible danger, and elemental destruction begins to ravage the Island.

Meanwhile, Skandar's sister, Kenna, longs to join him, and Skandar is determined to help her, no matter what. As the storm gathers, can Skandar find the key to stop the Island tearing itself apart before it's too late for them all?