evidence: Her second famous sleuth, Miss Jane Marple, was introduced in Murder in the Vicarage (1930). Miss Marple was an elderly spinster who had eccentric insights into private crimes and tragedies. Christie once told an interviewer, "I specialize in murders of quiet, domestic interest." And she wrote, "Every murderer is probably somebody's old friend." In addition to writing novels, Christie was a successful playwright. Her plays included Alibi (1928) and The Mousetrap, written in 1952, which remains the longest-running play in history. She was an incredibly prolific author, but her strategy was simple: she said, "The secret of getting ahead is getting started."