From end of Casefile #15 -- Five years ago Denny Payson's father died in a fire at the chemical plan where he worked. Now Denny's eighteen, and he's out to get the man he claims is responsible for his father's death -- Lucius Crowell, owner of the plant. There's a problem though. Not only is Crowell a respected businessman, he's running for publis office. No one believes Denny's charges. Frank and Joe decide to do some checking on their own. What they discover is Crowell's dirty past, and they realize Denny is in serious danger. With Crowell's hired thug on their trail, the Hardys have to stop Denny before he makes one last, final move.

From back of book -- Frank and Joe take on the case of Denny Payson, a friend who suspects that his father was murdered in a chemical plant fire five years ago. Lucius Crowell, owner of the plant, has taken care of Denny and his mother since the accident, but Denny is convinced that the fire was a cover-up for the factory's dirty secret. Now Crowell is running for public office, and Denny, an expert sports marksman, is determined to have his revenge. Nothing Frank and Joe say can convince him to give up his murderous plan. But another crack marksman -- a hit man -- is after Denny. Can the Hardy's save Denny before he turns on them?