As much as murder is a staple in mystery stories, so is love. Love may be a four-letter word, or the greatest of the trio of faith, hope, and love. It may appear in a mystery as the driving force behind the plot and the characters. Or it may appear as an aside in a sub-plot, a light spot in a heavy story. But it's there. Even Valentine knew love was worth dying for. An emotion this strong gets a lot of attention. Love has its own special day, St. Valentine's Day. According to legend, the Roman emperor Claudius Ⅱ needed soldiers to fight for him in the far reaches of the Roman Empire. He thought married men would rather stay home than go to war for a couple of years, so he outlawed marriage and engagements. This did not stop people from falling in love. Valentine, a priest, secretly married many young couples. For this crime, he was arrested and executed on February 14. St. Valentine's Day was off to a rocky start. Love, secrecy, crime, death. Love prevailed, and the day lost its seamy side. Valentine's Day became a day to exchange expressions of love. Small children give each other paper hearts. Adults exchange flowers and chocolates. Everyone has an attack of the warm fuzzies. Valentine's Day was popular in Europe in the early 1800s as a day men brought gifts to the women they loved. Gradually the expectations grew higher, the gifts got bigger, and eventually the holiday collapsed under the weight of the bills. It was revived when the custom of exchanging love letters and love cards replaced the mandatory gifts. A young man's love was measured in how much time he spent making a card with paper, lace, feathers, beads, and fabric. If the young man wasn't good with scissors and glue, the job could be hired out to an artist who made house calls. Valentine's Day grew more popular when machine-made cards became available, and people didn't have to make their own. In England in 1840, the nation-wide Penny Post made it cheap for everyone to send Valentine cards. In the United States, national cheap postal rates were set in 1845, and valentines filled the mail. 'Roses are red violets are blue' was a popular verse on Valentine cards. Other holidays are associated with particular flowers — the Christmas poinsettia, the Easter lily but Valentine's Day has no specific flower. Instead, it has colors — red, pink, and white. Red symbolizes warmth and feeling. White stands for purity. According to one romantic flower code, messages can be spelled out with flowers. Gardenias say 'I love you secretly.' Violets say 'I return your love.' Roses say 'I love you passionately.' Not surprisingly, the rose is now the top-seeded flower of love. But love mostly goes wrong in mystery stories, very badly wrong. Somebody does something wrong. Husbands, wives, and lovers kill each other, or kill for each other. Stack the characters up in any kind of love triangle, and watch how the angles are knocked off. Love is unrequited, thwarted and scorned. Murders are motivated by real or imaginary love, or the lack of it. That famous novelist Ernest Hemingway said, 'If two people love each other there can be no happy end to it.' So it goes in the mystery. Justice may win, but love is often the loser. In addition to plots driven by love, or the lack of it, there are sleuths who encounter love in the solving of the crime. The handsome or beautiful detective meets the suspect or the client. Their affair grows around, and in spite of, the murder. Think of the movies Casablanca and Chinatown. Barbara D'Amato offers a different twist on this theme in 'Hard Feelings'. The amateur sleuth meets a suspect or investigating officer and love smolders around the crime. Rose DeShaw's 'Love with the Proper Killer' is such a story. In a series of novels, if the continuing character is living a full life, love enters the storyline somewhere. Dorothy L. Sayers' sleuth Lord Peter Wimsey fell in l