On August 15, ten years after the Pacific War, five people meet at a station. Their purpose is to dig out a cache of morphine -- now worth sixty million yen -- that HASHIMOTO, an army medical officer, buried in an air-raid shelter in this city on the day the war ended. The five are: SHIMA, a beautiful woman who claims that she is HASHIMOTO's younger sister and that her brother is dead; NAKADA, a pharmacist; ONUMA, who owns a Chinese restaurant; YAMAMOTO, a thug; and SAWAI, who says he is a junior high school teacher. But HASHIMOTO originally had only three accomplices -- and hid the morphine late at night, so they did not know each other's identities. There is one person too many in the group, but they do not know whom. A butcher shop now stands over the old air-raid shelter. The five decide to rent a vacant house across the street, and dig a tunnel to the butcher shop. They set up a phony real estate office in the house, which the landlord has rented to them under the condition that they hire his son SATORU. They start digging, but run out of money to continue the work, and they leave the city to raise it. ONUMA watches for a chance to betray the others, and when he comes back to the city, he tries to conspire with SAWAI. Detectives call at the house to inquire about YAMAMOTO, who is suspected of committing robbery. Feeling that time is now against them, they start digging the tunnel again, but problems continue to occur, and relations among them deteriorate. The street is scheduled for a renewal project, and soon they will have to vacate the house. Tractors begin to appear on the street, which causes the house to tilt and throws the men in the tunnel into a panic. When they at last reach a point under the butcher shop, YAMAMOTO and SAWAI, who have been feuding, get into a fight. SAWAI kills YAMAMOTO, but he himself is crushed to death under the steel drum containing the morphine they have been after. SHIMA tries to entice SATORU -- whom she has seduced -- to kill ONUMA and NAKADA, so she can have the morphine to herself. In the meanwhile, however, ONUMA discovers that NAKADA is SHIMA's lover, and not one of HASHIMOTO's original accomplices. NAKADA and ONUMA square off to fight; SHIMA intervenes, and offers them each a beer. The beer is poisoned, and the two men die. SATORU witnesses this episode, panics, and reveals everything to the people of the town. In a heavy rain storm SHIMA runs away with the morphine, with the police in pursuit. She falls from a bridge into a raging river and dies.