Mark Conrad, a habitual drunk and troublemaker with a shady past, is expelled by Hong Kong police after one too many bar fights. He's sent to Macao on the Fa Tsan, a ferry owned by Captain Hart. Conrad's papers are out of order and Macao refuses him entry. Unable to go ashore, Conrad is a permanent passenger on the ferry with Hart, who detests him. It's all one long, lazy voyage for Conrad until one fateful trip when an encounter with a typhoon and pirates forces Conrad to choose between an aimless drifter's life and becoming a man again.

Through an experiment by Dr. Stewart with animal cells, a monster is created that is given the name Frankenstein. He is a gentle giant, but he escapes his guards and was supposedly killed on a mountain. After several years, a ship off the coast is attacked by a green monster, where the people think of Frankenstein. The green monster attacks the fortified country, in which the army is then called in for help. When a brown monster suddenly appears, Dr. Stewart understands that his Frankenstein was not killed, but has reproduced.