When a wave of phony $20 bills hits Honolulu, the Treasury Department asks Greg for help in finding the counterfeiters. Greg thinks the bills appear to be made by a former counterfeiter named Capt. Joe, who was supposed to have gotten out of the counterfeiting business and gone straight, but it turns out that Capt. Joe has been kidnapped by a gang of counterfeiters who want him to develop plates so they can counterfeit $50 bills.
Magazine writer Gloria Matthews asks Tracy to help her in an unusual matter. She's doing a story on Micho Koyoto, a Japanese marine who has been isolated in the Solomon Islands for the past 15 years and doesn't know the war is over. He is the heir to a large fortune back in Japan, but Gloria needs Tracy's help in convincing the Japanese soldier that the war is over.
Greg is hired by Bill Sinclair to guard a rare and valuable statuette called the Manabi Figurine until it can be appraised, at which time Sinclair plans to sell it and make a profit for he and his partners who found the item. However, the figurine is stolen from Greg's safe and someone winds up murdered. Greg, Tom and Lt. Quon work together to find the thief who stole the figurine and committed the murder.
Greg tries to help a young Asian woman who has arrived in Hawaii to take part in an arranged marriage. The trouble is, the man she is to marry is interested in only one thing--a pair of valuable antique vases she brought with her.
Laura Ingalls is accused of murder when her husband's mistress is found murdered. MacKenzie is asked to investigate the crime, but he discovers his life is also in danger because someone doesn't want him to arrive at a different conclusion.
The government brings in Tom to help investigate when defense equipment that was on a dock in Formosa turns up in Red China. He goes undercover, and quickly runs into a Chinese Nationalist "spy" who may or may not be a spy at all.