Billed as "an adult look at police life", The Detective went on to become one of the highest-grossing films of 1968 and one of the strongest box-office hits of Sinatra's acting career.

Both books utilize the third-person narrative in their storytelling, and rely on a wealth of introspective monologuing.

Joe Leland, a private detective, begins investigating a case for the recently widowed Norma MacIver.

It turns out that Leland and Colin MacIver served in the same military unit during World War II, but at different times.

Joe's partner, Mike Petrakis, managed to decipher Colin's coded notes and reveal a paper trail of corruption.