Dong Lei (played by Yang Kun), a wealthy second-generation, is about to marry his beloved girlfriend Su Jingjing (played by Ni Hongjie). He invites friends in the circle to join him on his honeymoon on a luxury cruise ship. Mystery novelist Liu Feiyun (played by Su Youpeng) and his agent Li Xiaofeng (played by Sun Yili) are on the list. On the cruise ship, there are handsome men and beautiful women, fine wine and delicious food, singing and dancing, just like a happy country isolated from the world. Liu reunited with Su Jingjing, the object of his secret love in elementary school, and also met Su's three beautiful female colleagues: Xiao Yang (played by Mao Junjie), Judy (played by Zhou Weitong) and Han Feifei (played by Wu Chenjun). As night fell, the guests of honor flocked to the deck to attend the masquerade, but at this moment of revelry and excitement, murders occurred one after another. The luxury cruise ship instantly turned into an isolated island full of murderous aura...