Missing (Chinese: 深海尋人; pinyin: Sam hoi tsam yan) is a 2008 Hong Kong dramatic fantasy horror film directed by Tsui Hark starring Angelica Lee.

Psychiatrist Dr. Gao Jing is scuba diving with a group of environmentalists attempting to bury carbon dioxide in the seabed when she is photographed by Guo Dong, the brother of her patient Xiao Kai.

Guo Dong takes Gao Jing to the Ryukyu Islands to show her the ancient underwater city of Yonaguni where he has hidden a ring that he will use to propose to his true love, but is beheaded in a mysterious accident.

She searches a shipwreck site with Guo Dong's friend Haiya Amu and finds a white-haired severed head that she believes to be her brother's.

Dr. Gao returns home to finds Xiao Kai speaking with a different accent and suspects that she is channeling the ghost of Su Zhenjing, a 24-year-old girl from Hualien.

Dr. Gao sends Haiya Amu to check whose head is in the canister but when she returns home she finds him dead with a knife in his back.

In the final scene the ghosts of Gao Jin and Guo Dong are shown swimming together around the underwater city of Yonaguni.