The author manages several plots and does it well. A work injured cop goes to recuperate at the rural home of an absent relative. He meets a young couple who then get murdered. With the aide of the local chief of police, he gets assigned to find the culprits.
During his investigation he meets an assortment of characters and each helps him work the case. There is a little romancing but this quickly becomes a story about chemical-biological weapons.
Off the coast of rural Long Island, not too far from Block Island, is another lesser known place called Plum Island, It's owned and operated by the American government and considered a "Top Secret" area. The island is approachable only by boat, and the channel between it and the mainland can often be so rough as to be dangerous, hard to cross in bad weather.
Plum Island is the site of an official laboratory charged to explore and control all kinds of biological and chemical weapons. The work is done by scientists, chemists, and physicists. The two young scientists killed worked at Plum Island.
While on the island they discovered a pirate's treasure. To avoid taxation and notoriety they endeavored to move the treasure to the mainland and rebury it, only to slowly re-discover it later. Their intent was to publicize the find, say the treasure was really quite small, pay the taxes, and then keep the bulk of it for themselves.
The rural area on the nearby mainland was small. Everyone knew everyone else. The investigation was finally narrowed to someone in the local population. As it proceeded many dangerous situations faced the intrepid "injured cop' hero of the story. From the first page to the last, our hero was portrayed as tough, wise cracking, and attractive to a few ladies on the island. Each one of the ladies was in a position to help him with the investigation. Each was also a romantic element of the plot.
The case was inevitably solved. The villain was predictable. The overall story stretched the imagination but maintained a convoluted mystery.
The side story promoted interest in weapons potentially more dangerous than any other. It asked the reader to think about the political implications, terrorist control, and every nations vulnerability.