Family secrets form the backbone of many delicious mysteries, and for good reason. It’s shocking to find out your neighbor or your coworker is not the person you thought they were, but it can up-end your whole world if you discover your loved ones have been hiding a deep, dark secret. They are your intimates, the people you live with or see often, and you’re supposed to know them better than anyone else. So learning a scandalous tidbit about a family member can sometimes change not just how you feel about that person, but also how you feel about yourself. Occasionally in real life, and often in fiction, these revelations can have deadly consequences.

When Kristine Fitzhugh was found dead at the foot of the stairs in her Palo Alto home, her doctor husband Ken Fitzhugh claimed it was an accident, blaming her slippery shoes for Kristine’s demise. The subsequent investigation found that Kristine had been beaten and strangled, and that someone made considerable effort to clean up after the crime. Cops eventually arrested Ken, and his motive turned out to be a long-held family secret: the couple’s oldest son was not fathered by Ken, but by a man Kristine had an affair with early in the marriage. Kristine had threatened to tell the young man about his true paternity, and Ken killed her to conceal the truth.

Author Liane Moriarty has spun many intriguing tales that hinge on secrets kept within families. These can be large and ominous, like murder or kidnapping, or smaller but no less devastating, like an affair or other indiscretion. The Husband’s Secret in particular explores how one man’s misdeed ripples out across everyone else around him, those whose choices become shaped either by knowledge of his secret or by the lack of it.

I love mining family secrets for book ideas. Secrets that aren’t harmful can even be fun and a way of deepening someone’s character. My grandmother and grandfather were married for sixty years, but I discovered after his death that this had actually been a second marriage for her. My straight-laced old granny had run off with a beau at age fourteen to get married! I’m just as glad this didn’t work out, because if it had I wouldn’t be here, but I enjoy thinking about her as someone who took a reckless chance in the name of passion. Maybe I’ll put her in a book one day…