Detective Dixon Franklin is back again; this time hired by Ella and Ray King, a husband-and-wife mystery-writing team who appear to be the targets of a killer. Dix's job is to find the culprit and bring him to justice before the King's who-done-it days are really done

World War II veteran Dix Franklin can't seem to find a break. He goes from job to job until he passes a Private Eye Correspondence School course. His first case seems simple enough---find a missing dog, but he ends up entangled with foreign spies, nuclear scientists and an international kidnapping plot. Along the way, Dix finds a soul mate in pretty Penny Parker and together, the two of them try to unravel a double mystery.

The third mystery investigated by young detective Dixon Franklin has him on the trail of the stolen plans for the world's first computer