The Problem of the Lost Radium is a mystery novel written by Jacques Futrelle. The book follows the story of detective Craig Kennedy, who is called upon to investigate the disappearance of a valuable piece of radium. The radium was being transported on a train, but it mysteriously vanished during the journey. Kennedy and his assistant, Walter Jameson, set out to solve the case, interviewing suspects and gathering clues along the way. As they delve...