The Knowledge

London cab driver Robbie Parsons knows every street, every theater, every landmark in the city by heart. In the backseat of his classic black taxi is a man with a gun in his hand—a man who just a few minutes ago brazenly committed a crime in front of the Artemis Club, a rarefied art gallery-cum-casino, then jumped in and ordered Parsons to drive.
As the criminal eventually escapes to Nairobi, Detective Superintendent Richard Jury comes across the case in the Saturday paper—and immediately recognizes one of the victims of the crime. Jury soon enlists Melrose Plant, Marshall Trueblood, and his whole gang of merry series characters to contend with a case that takes unexpected turns into Tanzanian gem mines, a casino in Reno, Nevada, that’s no longer in business, and a pub that only London’s black cab drivers, those who have “the knowledge,” can find.

https://www.marthagrimes.com/books/richard-jury-series/the-knowledge/