Kellerman's Delaware mysteries always teeter towards soap opera and occasionally fall in. This is one that fell. Depending on you, the reader, that can be either good or bad. For me, the other elements either make the book good or bad. I like 'The Web'.
Another element is that Kelleman's plots always contain Truth - of historical facts or recent headlines on CNN - which he heavily fictionalizes. Since I read the news as obsessively as I do novels, and I have done so for 50 years, plus my memory is not yet decaying, I am always feeling that sense of déjà vu whenever I read a Delaware mystery. As fantastic as they might seem to less informed readers, the only things fictionalized are that these events happen to one guy in his life as a California therapist. Kellerman also conflates events that might have actually occurred decades apart by putting them into the same time era in one location, and of course while these events happened to different real people once, in these books all of the characters are imaginary people. Kellerman also obviously imagines what the real people who lived might have felt going through the actual events in history, as well as constructing heroic behaviors for his fictional characters.
Whatever. The fact remains is that as far out as these plots seem to be, they actually have happened on some level to real people at some point in the past somewhere in the world and you can go online to read the real story, or a least find several real stories that match many of the plot bullet points, despite it maybe actually happening to Black-Americans and mental hospital patients in the American south instead of on Aruk, or being a conflation of actual intentional radiation poisoning of soldiers in American deserts and Pacific Islanders in WWII so that there are still islands out there in real life no one can live on today due to the nuclear bombing America did in the name of scientific experimentation. There are also 'hot' spots in American wastelands today, too. Lastly, the recent attempt by the corporations that backed George W. Bush's Iraq war to steal markets and businesses in Iraq for international corporate profit only demonstrate that business rape is an ongoing enterprise today as well. Without the light of journalism and government without corruption, business is selfish, mean, murderous and psychopathic, and when coupled with a military partnership, it is tripled in effect against common human decency. There are thousands of examples of business/military partnerships throughout human history up through current times where entire countries are raped and/or destroyed for the strictly monitory benefits of the few people, the 1% if you will, at the top. These places are easy to spot - despite millions and billions of dollars going into a country or geographical area, there are few schools, clinics, business opportunities or infrastructure like roads and electricity and clean water on tap.
So, no, I don't feel these mysteries border on fantasy, only soap opera. Sometimes.