During World War II, Japan sends gold to the Phillipines. After the war, the gold is lost in the bay of Manille. Former soldier Takeichi Matsuo is now working as a business executive. He meets Mintsura Gunji, the boss of a large company, who offers him to go to the Philippines and bring back the gold.

In Hong Kong an International Secret Police (ISP) Agent is murdered while investigating ZZZ, a group bent on assassinating the Prime Minister of Buddhabal. ISP Agents Carter and Kitami are assigned to the case. When the Prime Minister arrives in Tokyo for a friendship visit, Carter and Kitami are on hand to protect him. On hand, too, are assorted ZZZ blackguards. Several attempts on the Prime Minister's life fail, until finally the ZZZ introduces a new device designed to eliminate not only the Prime Minister but the ISP Agents as well: THE KILLING BOTTLE, then, is a pocket-sized container filled with a substance that can expand to thousands of times its size and throttle its victim, then disappear leaving only the corpse.

Klima, Deputy Minister of Industry of the Republic of Alabanda, has come to Japan to purchase materials for the water dam construction. Kitami, who called himself a salesman and met with Klima, acts as his bodyguard. However, Kitami learns that a large number of industrial cylinders unrelated to dam construction have been purchased, and Klima secretly confined her secretary, a former army colonel, and threatened to produce poisonous gas. Klima packed the gas in a cylinder and sent it to Alabanda in an attempt to cause a civil war between the government and the tribes. Around that time, Klima secretly investigated Kitami's identity and learned that he was a secret agent.

An American journalist stationed in Japan is given a mysterious injection by a mad scientist, turning him into a murderous, two-headed monster.

A massive underwater volcano erupts and puts a group of investigative scientists in danger. They are rescued by an atomic super submarine named The Alpha under the command of Captain McKenzie. The group is quickly taken to a vast underwater city known as Latitude Zero, a fantastic, Atlantean type utopia, a world beneath the ocean with its own sun. It is soon discovered that Captain McKenzie is at war with the evil Dr. Malic, a cruel scientist who wishes to rule mankind all the while conducting genetic experiments on humans and animals. Malic sends his agents to kidnap Dr. Okada, a human scientist who has created a serum that can immunize exposure to radiation.