On a rainy night in Shenzhen, a female prostitute named Sze-kam Oi-yee was strangled to death by female wanted criminal Yip Siu-ngan in order to assume her identity. Ngan poses as Yee and passes the customs and successfully arrives in Hong Kong. After reporting the loss of her ID card, she successfully obtains Yee's identity. Yee has a Hong Kong ID because her husband is a Hong Kong resident, who at the time was waiting for his wife's arrival.