Dan Arrow and the New World Order by Edward S. Baker

Dan Arrow is a private detective who’s catapulted into a world he never imagined when a guy named Billy Powers dies the night before their first meeting. In the mail the next morning, Dan receives Powers’s notebook, which is full of handwritten comments and clipped articles about seemingly unrelated events. Initially dismissing the notebook’s contents as the work of a crackpot, Dan soon meets Powers’s wife and discovers that there’s more truth than fiction about aliens cooperating with international governments to achieve covert agendas.

Dan wouldn’t have called his ex-girlfriend, FBI Special Agent Mona Casola, except that his client is dead and Mona’s employer has classified it as a suicide. Thrown together again, the duo’s investigation takes them into deep underground military bases, where alien species are working with several governments to establish a New World Order. Then, when Mona is taken captive by a reptilian leader, Dan must choose between rescuing the love of his life or stopping the coronation of an evil leader and the unleashing of a global pandemic as the NWO agenda is set into motion…