Past and Present Danger — Franklin W. Dixon

AN UNDERCOVER STORY BRINGS
CRIME OUT IN THE OPEN!

Frank and Joe's aunt Gertrude leads a pretty quiet life -- until an old high school friend turns up in Bayport. Clayton Silvers once had a distinguished career as an investigative reporter. Then he was accused of falsifying some of his articles and even taking money to expose his subjects. Now he's in town, working on the explosive story that he says will be his comeback.
Aunt Gertrude staunchly maintains her friend's innocence, but the Hardys aren't so sure that Silvers is a sterling character. Since he's been around, the danger level has escalated. Now the Hardys are the ones being watched and stalked, their every move monitored. Silvers is playing a high-stakes game, and the Hardys don't want to be on the losing end!