In 1917, 18-year-old Ruth Cruger disappeared. She’d last been seen getting her ice skates sharpened in the motorcycle shop of a man named Alfredo Cocchi. Newspapers reported that she probably ran off with a boyfriend, and New York police said that there were no clues to go on. But an investigator named Grace Quackenbos Humiston decided that she would do whatever it took to find her. She became known as “Mrs. Sherlock Holmes.” Brad Ricca’s book is Mrs. Sherlock Holmes: The True Story of New York City’s Greatest Female Detective and the 1917 Missing Girl Case That Captivated a Nation.