The Last Message (1975)

"The moment you are convinced that you are a genius, already you are an idiot!"

Li (Sam Hui) works at a sanitarium as a male nurse, and Ah Tim (Michael Hui) is a handy man. One day, a bearded old man is sent into the sanitarium with a large bag. Ah Tim manages to steal the bag, and finds antique fragments inside. When the old man dies, the pair learn from his daughter that there is a sunken vessel that is loaded with much more than they already have, so they decide to go after the sunken treasure.