Crime fiction that takes place on the London Underground: A List
Novels
London Underground by Chris Angus
Death of a Ghost by Margery Allingham
Whispers Under Ground by Ben Aaronovitch
The Da Vinci Code by Dan Brown
The Man in the Brown Suit by Agatha Christie
Patriot Games by Tom Clancy
Bryant and May Off the Rails by Christopher Fowler
The Ministry of Fear by Graham Greene
Rogue Male by Geoffrey Household
Baptism by Max Kinnings
The Death of Laurence Vining by Alan Thomas
King Solomon's Carpet by Barbara Vine
Vanished by Tim Weaver
The Blue List by Nigel West

"The Adventure of the Bruce-Partington Plans" by Arthur Conan Doyle
"Crocodile Lady" by Christopher Fowler
Non-Fiction
Underground Overground by mystery author Andrew Martin: social history of the underground railway.
Just an FYI, Mystery Readers Journal will have an issue on Murder in Transit this year.