The Green Ripper is the eighteenth of 21 Travis McGee

Travis McGee

Travis McGee is a fictional character, created by prolific American mystery writer John D. MacDonald. Unlike most detectives in crime fiction, McGee is neither a police officer nor a licensed private investigator; instead, he is a self-described "salvage consultant" who recovers others' property...

 novels written by John D. McDonald. It won the National Book Award

National Book Award

The National Book Awards are a set of American literary awards. Started in 1950, the Awards are presented annually to American authors for literature published in the current year. In 1989 the National Book Foundation, a nonprofit organization which now oversees and manages the National Book...

 for the category of mystery in 1980, and was the first and only book in that category to receive the award. The plot is centered on revenge

Revenge

Revenge is a harmful action against a person or group in response to a grievance, be it real or perceived. It is also called payback, retribution, retaliation or vengeance; it may be characterized, justly or unjustly, as a form of justice.-Function in society:Some societies believe that the...

 against a secretive, terrorist cult that is responsible for killing McGee's lover Gretel. The title is a word play on the name of the Grim Reaper.