The Key (Hardcover) (ISBN-13: 9781639851737)

After National Park Service Ranger Sarah Higgins helped US Park Police Lieutenant Mike Finnegan solve the theft of a priceless artifact from a federal building in lower Manhattan, she informed Finnegan that she began to receive anonymous letters in her mailbox. The first envelope contained only a key. There was no message or return address. Subsequent envelopes, she said, contained hints to the whereabouts of former superintendent Joe Kozlewski who left the state abruptly after confessing that he assisted the perpetrators who committed the crime in the building he managed.

Finnegan, a veteran police officer, ignores the advice of friends and colleagues. He is determined to discover the source of the letters and how they relate to the missing superintendent. He is willing to stake his reputation and career on finding out the true significance of the key. But Finnegan finds dramatic roadblocks at every step. Police, for example, find the body on a downtown Manhattan sidewalk of the mastermind of the theft. Two other persons close to Kozlewski die of suspicious causes. Another possible source of information unexpectedly disappears without providing the post office with a forwarding address, and a fifth suspect sells her house suddenly and leaves town.

When a tip finds its way to Finnegan's desk from a kindly parish priest about a parishioner acting strangely, the federal police officer suddenly realizes that he's close to solving the mystery and must act quickly. His hunch proves correct. He requests and secures cooperation of other law enforcement agencies who track the parishioner to where Kozlowski is hiding.

It's not until Sarah Higgins reveals a startling secret about the key, however, that Finnegan is able to finally close the file.