A long time ago in another country, I nearly killed a woman.

It’s a particular feeling, the urge to murder. First comes rage, larger than any you’ve ever imagined. It takes over your body so completely it’s like a divine force, grabbing hold of your will, your limbs, your psyche. It conveys a strength you never knew you possessed. Your hands, harmless until now, rise up to squeeze another person’s life away. There’s a joy to it. In retrospect it’s frightening, but I daresay in the moment it feels sweet, the way justice feels sweet.

Agatha Christie had a fascination with murder. But she was tenderhearted. She never wanted to kill anyone. Not for a moment. Not even me.

“Call me Agatha,” she always said, reaching out a slender hand. But I never would, not in those early days, no matter how many weekends I spent at one of her homes, no matter how many private moments we shared. The familiarity didn’t feel proper, though propriety was already waning in the years after the Great War. Agatha was upper-crust and elegant, but perfectly willing to dispense with manners and social mores. Whereas I had worked too hard to learn those manners and mores to ever abandon them easily.

I liked her. Back then I refused to think highly of her writing. But I always admitted to admiring her as a person. I still admire her. Recently, when I confided this to one of my sisters, she asked me if I had regrets about what I’d done, and how much pain it caused.

“Of course I do,” I told her without hesitation. Anyone who says I have no regrets is either a psychopath or a liar. I am neither of those things, simply adept at keeping secrets. In this way the first Mrs. Christie and the second are very much alike. We both know you can’t tell your own story without exposing someone else’s. Her whole life, Agatha refused to answer any questions about the eleven days she went missing, and it wasn’t only because she needed to protect herself.

I would have refused to answer, too, if anyone had thought to ask.