Casey is only fifteen years old when her stepfather plans to marry her to a perverted and brutal man twice her age. However, minutes before the wedding, Casey flees into the jungle where she is rescued from her pursuers by a mysterious woman who sets the young, scared girl on the path of an epic pirate life, full of adventures, dangers, personal struggles, and world discovery.

Struggling with her own fears and desires, Casey balances between being just a teenage girl confused about love and her own sexuality, and becoming a ruthless pirate seeking revenge over those who have taken all she had away from her.

Casey strives to win the trust of the Twenty-One Butterflies, an elite group of female pirates living on Butterfly Islands, a mystic place filled with dazzling butterflies by day and swarms of moths carrying atrocious parasites by night. A disastrous trip to God’s Mercy, a floating city in the sky, changes everything. While trapped once more in the hands of her former husband-to-be, Casey suddenly finds out that there is a traitor in their midst. From then on, it is a race to save her new friends lives and escape from the man who wishes to make the young girl his wife and a slave to his twisted desires.