All Grass Isn’t Green was the final Cool/Lam case. Gardner got the Advanced Review Copies just days before his death. While the book was not up to Gardner’s best, his perseverance is impressive given that he was dying of a particularly painful form of cancer while writing.
Mr. Calhoun wants the detectives to find Colburn Hale, a writer who has disappeared along with Calhoun’s girlfriend, Nanncie. Lam determines Calhoun’s identity and quickly gets a line on the writer and ladyfriend in Mexico. Gardner interposes here to talk about the Mexican culture and people, more like his travel books than a fast-paced mystery. He again interjects into the story to explain about marijuana when it appears that Lam has stumbled across a smuggling ring.
The series does not have any closure, despite the fact that Gardner knew of his impending death. Cool and Lam remained just as they had been for 29 tales, ready for work and looking for clients with cash.