During a high-speed motorboat chase with a criminal, Cheung Chau police officer Wong Tai-mui gets herself trapped in a waterspout, accidentally opening a time portal. She travels back 200 years to 19th century Hong Kong, a time when the island was under Qing rule. Using her knowledge of the future, which she keeps in an e-book, she saves a family of pirates from a deadly naval battle against the Qing naval fleet led by Prince Man-ho, the eleventh son of the Jiaqing Emperor. Puzzled by her mysterious origins, the family remains wary of Tai-mui and is hesitant in trusting her. Meanwhile, at the royal court, Prince Man-ho becomes jaded from politics and family feud and decides to let go of his ambition for the crown.