In a sealed-off city, a young woman, Lena, is running for her life. She has been sentenced to death and her only way to survive is to trust those she has been brought up to fear - those with magic.

On the other side of the locked gates is a masked lady, Constance, determined to find a way back in. Years ago she escaped before her own powers were discovered. But now she won't hide who she is any longer.

A powerful and terrifying storm cloud engulfs the city. But this is more than a thunderstorm. This is a spell, and the truth behind why it has been cast is more sinister than anyone can imagine...