Lua Klein is the lover and fiancée of Ladd Russo, a sadistic hitman in the White Suits gang. She is a fair-haired young woman with green eyes, often described as beautiful but with a vacant, serene expression that can appear lifeless. Her surname is of German origin, suggesting German ancestry. Lua accompanies Ladd and his crew during their hijacking of the Flying Pussyfoot train over December 30–31, 1931, and remains by his side throughout the violent events. She is deeply devoted to Ladd, and her strongest motivation is her desire to be killed by him. She appears to derive pleasure from his promise that he will kill her last, after everyone else, and this devotion is so complete that she would willingly put her own life in danger for his sake. During the hijacking, Ladd sacrifices one of his hands to save her life, an act that underscores the intensity of their bond. Lua’s personality is calm, quiet, and gentlewoman-like; she rarely shows strong emotion and often seems detached from the chaos around her. In the light novels, she has a peculiar hobby: she enjoys assembling blank jigsaw puzzles, painting a picture on the completed surface, and then deliberately breaking the puzzle and laughing at the pieces. This behavior hints at a quiet but unusual inner world. After the Flying Pussyfoot incident, Lua is one of only two people from the White Suits who are not arrested; she returns to Chicago while Ladd is sent to prison. She later reunites with him after his release from Alcatraz through the help of Graham and Shaft, and in a later conversation with Graham, she remarks that she would consider the last human on Earth a hero. Lua possesses keen instincts and outstanding insights, though she does not engage in combat or direct action. Her role in the story is primarily that of a devoted partner whose love for a violent man forms a calm counterpoint to the mayhem around her, and she provides a subtle psychological depth through her peculiar pastimes and her unwavering acceptance of Ladd’s murderous nature.