This time the criminal at large is a con artist who poses as a "displaced person" in need of quick cash. Each of the con man's victims is offered a handful of genuine "perfect cut" blue-white diamonds for a fraction of what they are worth--but by the time the victim has made the purchase, the real gems have been switched with all-but-worthless zircon. When Friday (Jack Webb) and Smith (Ben Alexander) catch up with the phony diamond merchant, he minces no words congratulating himself for proving the old adage "You can't cheat an honest man." This episode is based on the Dragnet radio broadcast of February 16, 1954. ~ Hal Erickson, Rovi