Flashbacks are the theme in these new crime and mystery novels. Lee Child’s Night School takes place in Jack Reacher’s military past. An assignment to additional training turns out to be a mission to track down a dangerous Jihadi. In No Man’s Land by Dave Baldacci, John Puller (The Escape) revisits his mother’s disappearance 30 years ago. In The Wrong side of Goodbye, Harry Bosch, now retired from the LA police, is asked by a wealthy client to find out what became of a former girlfriend who disappeared with his child by her 65 ago. And in Penny Jumper by James Grippando, a young astrophysicist teams up with her mother’s former colleague at MIT, hoping to help finish a project which her mother had been working on when she died. But when the project’s algorithms are applied a stock-trading scheme, she finds herself over her head.