“Due diligence. Utter that dull gray phrase around a pack of corporate lawyers and watch them leer. That’s because the final tab for the due diligence in a significant transaction will easily exceed ten million dollars. Those kinds of numbers enchant even the most somber of practitioners.”

The plot revolves around an accountant who was doing due diligence on a company before a merger could take place. Rachel had received a call from him explaining he needed her advice on some details of the merger. When his body is found in the basement having gone through a trash compactor, Rachel is hired to help clean up some of the affairs and discovers an intricate web of deceit and malfeasance. Soon her investigation leads to a presidential candidate and what he might have done many decades earlier and whether doing something that might benefit millions of people but leads to the deaths of some elderly patients might be ethically suspect.

Each of Kahn’s books takes a legal issue and builds a plot around it. There’s usually some kind of list with obscure combinations of letters and numbers Rachel must decipher. While the details of the characters appear repetitive from one book to the next, I didn’t find that as disconcerting as have some readers.

Some interesting history of trademarks. I knew little of their origin and raison d’etre. “During medieval times, trademarks became a symbol of responsibility as the powerful guilds of Europe required their members to each use a unique mark. That way a defective product could be traced back to its maker. A trademark was thus the highly personal symbol of a single worker: when his life ended, so did his trademark. By the middle of the twentieth century, however, it had metamorphosed into the multibillion dollar world of brand-name marketing—a world where a single word, such as Xerox or Corvette or Chanel or Kodak, can be worth hundreds of millions of dollars.”

Not to mention that St. Louis became home to many brands of beers because it’s built over the top of hundreds of limestone caves. I just had to check out whether all this was a figment of Kahn’s imagination. It is not and the caves play a central role in the solution to the puzzle. Note that claustrophobic activities appear in other of Kahn’s novels. (http://books.google.com/books?id=A-qxHKZcF_AC&pg=PR6&dq=st.+louis+caves&hl=en&sa=X&ei=_mNCVKejOs3-yQSCyYCQCg&ved=0CDIQ6AEwAA#v=onepage&q=st.%20louis%20caves&f=false) ( )