The Japanese attack Pearl Harbor, Charlie is volunteered to become a member of the Army's new Security Service because the work he's done at home in Honolulu has been noticed by influential members of the government. He's ask to move his family to San Francisco and train a team to seek out spies and felons who do harm to the country in time of war. His team uncovers plots against a government radar installation in Moon Valley and theft on a grand scale. When Chan's first team is murdered by a bomb, he has to rebuild with volunteers, most just kids like his number one Jimmy. Jimmy, who has since been rejected as a pilot, is delighted at the opportunity to become a detective and work alongside his father. Jimmy recruits his friend from high school who is half Japanese and half Chinese and who can read and write and speak both languages. He turns out to be a brilliant young man. He helps them decode messages hidden in an underground Japanese newspaper. Together they track down a theft ring working inside the Army Transport Command misappropriating millions of dollars' worth of government supplies.