Fabian, the leader of a spy ring, plots to disrupt the peaceful relations between England and France by blowing up the French fleet as it steams through Port Said in the Suez Canal. Although Fabian is posing as a ventriloquist to hide his sinister activities, British agent Burke has infiltrated the ring under the alias of Danforth, and has warned the French of imminent danger. Consequently, the arrival of the fleet has been delayed. Meanwhile, Mr. Moto, an agent of the International Police who is masquerading as an antique dealer, is also trying to uncover Fabian's plot. After ordering Eric Norvel, one of his men, to trick the admiral's wife, Madame Delacour, into revealing the arrival date of the fleet, Fabian discovers that Danforth is a British agent, then disposes of him by cutting Danforth's lifeline on the diving bell into which he is submerged near the site of the explosives. Thus Fabian cleverly makes it seem as if the British are responsible for the sabotage. Becoming suspicious of the antique dealer, Fabian orders his girl friend, Connie Porter, to follow him. Connie's report confirms Fabian's suspicions that the antique dealer is Mr. Moto, and Fabian orders that he be killed, but Moto cleverly escapes. As the fleet steams into port, Fabian readies to give Norvel the signal to detonate the explosives, but Moto intercepts Norvel and sets off the explosives before the fleet can reach port. Fabian then tries to kill Moto himself, but his attempt is cut short when Connie, who has discovered his treachery, shoots him.