The Keeper: Satan's Nurse (The Keeper #5)

Vatican secret agent Vincent, aka The Keeper, travels to a Mexican island to track down members of The Order of the New Temple, a powerful organization with sinister plans to manipulate the world stage. As he fights off killers and crocodiles in the Caribbean mangroves with the help of a local priest and discourages assistance from a group of vigilantes hunting down war criminals, Vince makes some unsettling discoveries in the research lab run by modern-day Nazis and uncovers a dark secret about his own past.