The first of the revised Hardy Boys stories, "The Tower Treasure," was relatively tame, even though there were a couple of moments of near danger. In the second book in the series the danger is turned up; the bad guys have guns and they are not afraid to use them!
Their father, the famous detective Fenton Hardy, invites the Hardy Boys on a case. This time the Hardy Boys accidentally observe smugglers attacking a man on the ocean. Before the boys can see what happens to the man they hear a cry from an abandoned nearby house, which is perched on a cliff overlooking the ocean. Their search is fruitless, and on returning where they had left an expensive telescope, they discover the eyepieces are missing. The mystery begins.
The smugglers are bringing rare drugs into the country, by means unknown. Fenton Hardy believes the leader of the smugglers to be a tough character named Snattman. Fenton Hardy disappears during the investigation, leaving the boys with an even bigger mystery, and their mother with concerns regarding Fenton's safety.
As happens often with the Hardy Boys, a group of their friends pools their resources to locate the smuggler's hideout along with who the smugglers are. Along the way they discover that their father was kidnapped and held captive by the smugglers, and they may yet murder him!
The exciting conclusion of this book involves the Coast Guard, secret passages, a mysterious cargo ship, and a man named Singh. As the battle between the smugglers, led by Snattman, and the police, the Coast Guard, and Joe, Frank, and Fenton Hardy rages on, everyone is in danger because the smugglers have guns and are not afraid to use them.
While the Hardy Boys have not aged well, as reading material for an increasingly younger audience they are excellent. The stories were once recommended for children ages 10 to 14. As children are exposed to more violence and seem to require greater levels of stimulation, the recommended age range has move to 9 to 12. I think any child capable of reading some of the challenging words in these books will enjoy them, regardless of how tame most of the action may be. Once a child has reached age 12 or so the stories may be of less interest, but given the combination of mystery and action, these books remain good safe choices for parents who want to know what their children are reading.