Kang Jiyoung’s Mrs. Shim is a Killer (Harper Perennial, 320 pages, $25), originally published in Korea in 2010, is absolutely delightful. Shim Eunok, a 52-year-old widow and mother of two, is barely making ends meet. When the butcher shop at which she works closes unexpectedly, throwing her out of work, Mrs. Shim answers a help-wanted ad posted by the Smile Private Detective Agency. Much to her surprise, she’s hired on as a contract killer. What a charming character is Mrs.