In 1929, in Tokyo, Nick Condon, the editor of the English-language newspaper Tokyo Chronicle , reports that Japan's prime minister, Baron Giichi Tanaka, has authored a document called the "Tanaka Plan," which, among other things, advocates the military conquest of America. Concerned by the report, Capt. Oshima of the Tokyo police and Kajioka, the chief of the Secret Police, question Nick, who insists that he picked up the story over the news wires. In private, however, Nick admits to his publisher, Arthur Bickett, that he wrote the piece based on rumors. Later, in an American bar, Nick meets reporter Ollie Miller and is surprised to discover that he has a roll of cash and is sailing for America that night. Ollie refuses to tell Nick who paid him the money, but advises him to leave Japan as soon as possible. Later, when Nick arrives at the dock to say goodbye to Ollie and his wife Edith, he is accosted by Oshima and Kajioka and then finds Edith strangled to death in her cabin. Nick spots a woman lurking around the cabin and chases her, but she escapes. Nick then heads for his house, having learned from friend Charley Sprague that Ollie is looking for him there. As soon as he arrives, Nick hears gunshots and discovers a fatally wounded Ollie. Before dying, Ollie entrusts Nick with the Tanaka document, which the Chinese government had paid him to smuggle out of Japan. Hearing knocks at his door, Nick hides the document behind a portrait of Emperor Hirohito, and when Oshima and his men burst into the room to search for the plan, they avoid the portrait out of respect. Nick then uses his newly acquired judo skills to escape the police, but Oshima finally knocks him out. After spending the night in jail, Nick is released, but discovers that all evidence of Ollie's murder as well as the document have been removed from his house. Hayashi of the Foreign Office then takes Nick to Tanaka's home, where unknown to Nick, Tanaka has been meeting with the woman from the boat, the half-Chinese, half-European Iris Hilliard. While insisting that the Millers are alive, Tanaka, Kajioka and Col. Tojo of the Japanese Army advise Nick to return the document, which they maintain is a forgery. Nick balks at the suggestion and later asks Charley to write an item announcing his departure for America in ten days. At the bar, Nick, who is being followed by secret police agent Hijikata, is introduced to Iris by Joe Cassell, a reporter who until recently was stationed in China. Nick is attracted to Iris and begins to romance her. Although Nick reveals little about his situation, Iris reports to Tanaka that she is sure he has the document. Iris then asks Nick what he knows about the document, but he feigns ignorance. When Nick hears that Bickett, under pressure from the Japanese government, is replacing him with Joe, he writes a column denouncing Joe for embezzling funds raised in America for Chinese refugees. Disgraced, Joe begs help from Tojo, for whom he has been secretly working, but Tojo refuses him. Filled with remorse, Joe then offers to smuggle the document out for Nick, but Nick turns him down. After Joe reveals that he set him up with Iris, Nick storms over to Iris' apartment and accuses her of trying to frame him as a spy in order to force him to give up the document. Unaware that Oshima has planted listening devices in her place, Iris, who has fallen in love with Nick, confesses to him that she has the document, having taken it from his house while he was in jail. Although Iris assures Nick that she can obtain verification of its authenticity from a witness to the document's signing, she is confronted by Tanaka soon after Nick leaves. Tanaka gives Iris two hours to reveal the witness' name, and when the deadline passes, he orders Tojo and fellow officer Yamamoto to execute her. Having failed in his mission, Tanaka then commits hara-kiri. A week later, Nick, who is about to sail for America, is alerted by embassy official Johnny Clarke that a warrant for his arrest has been sworn out. Having gotten a message from Iris asking him to meet her at a shack on the wharf, Nick arranges to rendezvous with Johnny in one hour and heads for the wharf. Iris, who managed to escape her apartment, has brought Prince Tatsugi, the witness, to the shack to sign the document in front of Nick. Although Tatsugi knows that he will be killed as a traitor, he signs the document, saying that Tanaka's militarism will destroy Japan. After Tatsugi leaves, Iris and Nick prepare to flee Japan in a fishing boat. Before they take off, Oshima, who has shot Tatsugi, starts breaking down the door to the shack. Nick sends Iris on with the document, then challenges Oshima to hand-to-hand combat. After Nick beats Oshima unconscious, he eludes Hijikata and rushes to the U.S. Embassy. As he approaches the building, he is shot by snipers on orders from Yamada, who searches in vain for the document. Having heard the shots, Johnny runs out of the Embassy and informs Yamada and Kajioka that the U.S. government will be investigating the incident. Although Yamada suggests that they "forget everything" and "forgive," Nick, wounded but alive, vows to "first get even."