After escaping a violent coup led by their tyrannical stepfather, Crown Princess Zara Calliste and Crown Prince Zayne Calliste vanish beneath the sea. Believed dead by the kingdom they once called home, the twins wash ashore on a small island under the protection of the Whitebeard Pirates, barely clinging to life. The island’s doctor recognizes them immediately. Years ago, Zara saved her life without asking for anything in return. Unable to repay that kindness until now, she sends an emergency Den Den Mushi call to the Whitebeard Pirates, begging Marco to come heal injuries no ordinary doctor can treat. She asks for only one other thing: “If they survive… please don’t make them go back.” When the Whitebeard Pirates arrive, they expect to rescue two strangers. Instead, without realizing it, they welcome home two members of their family. Long before anyone discovers the truth—that Zara and Zayne are Whitebeard’s biological children—they become his children in every way that truly matters.