Dear Abigail,

I have been happily married for seven years, and I’ve known my husband for eight and a half. Like any couple, we’ve had our ups and downs, but overall we’ve grown closer, while building a life together and raising our three young children.

This week, completely out of the blue, I received an email from someone I don’t know. She said she felt I deserved to know something important—that over 10 years ago, my husband sexually assaulted her.

I spoke to my husband immediately. He told me that around that time, he had a brief relationship with this woman, and they hooked up a few times. He said she became unstable and obsessive, and that he cut off contact. According to him, she later accused him of rape, which he firmly denies.

Understandably, this has shaken me.

I trust my husband. Our marriage is built on that foundation. He has earned my complete trust in a thousand ways in our time together and has always been a man of upstanding character. I know in his heart he is a kind and good man.

And yet, I can’t ignore the pit in my stomach.

I’m torn about what to do next. Should I respond to her and hear her side of the story? Or is trusting my husband enough?

I don’t want to invite unnecessary chaos or give attention to someone who may be unstable. But I also don’t want to dismiss something serious or risk being naive.

—A deeply conflicted wife, 35

Dear Deeply Conflicted Wife,

A brilliant friend, a fellow law student at the time, once pointed out to me an ontological unfairness in criminal law. “You ever notice that the criminal code mostly punishes male-typical forms of violence?” he said. “Female-typical social violence—rumor, cruel innuendo, ostracism, alienating friends from you—largely goes ignored?” It was the sort of unconventional insight that came at me sideways and stuck. Because, of course, he was right.

Pop another guy in the nose, and you’ve committed an assault. You face expulsion from school or even a criminal record. But spread a devastating rumor, level a false accusation—and you can inflict bottomless, ongoing anguish on your target without anyone calling the cops on you. You’ll rarely even suffer reputational consequences yourself.

Over a decade after she briefly dated your husband, a woman has detonated a dirty bomb in your family. Her conduct will leave no physical trace. But by inviting you to mistrust your husband, the emotional pain and havoc visited on your family are potentially limitless. Do you imagine she is honestly trying to protect you or your children from your husband of nearly eight years? Does that seem even remotely credible? Don’t lie to yourself: It isn’t...