When they arrested my boyfriend for murdering my sister, I was there. I watched out his bedroom window as the police affixed handcuffs to his thick, strong wrists and took him away. As he got into the back of that squad car, I was certain of two things: First, that Thomas Emanuel Callahan was guilty and, second, that I loved him enough to tell anyone who would listen that he wasn’t.

Marnie and I used to be close—back when we actually asked our mother to buy us matching dresses and begged to be allowed to sleep in the same bed. Before we grew up.

In our house, World War III was waged silently. Like so many other wars, it began with a quiet catalyst that radiated outwards. Shrapnel embedded itself deep within flesh, bombs were detonated, and hostages were assassinated. In the end, there were many casualties in my war against my sister. I refused to let Tommy become one of them.

In our house, a piece of pie was never just a piece of pie. It was a measure of our mother’s love. Any discrepancy between the sizes of our slices telegraphed the difference in our worth.

I’m not sure exactly when it began to bother me that—other than on my birthday—Marnie always got the bigger portion of dessert. But I remember the first time I spoke up about it.

I was eleven. Marnie was twelve. We were Irish twins at only eleven months apart. It was the same day Dad announced he was walking out of our lives forever. Mom didn’t even cry.

“He’ll be back,” she said, even though no one believed her.

Dad had already met someone else. Her name was Ruth. She smelled of pine trees, youth, and betrayal. Mom smelled like bacon grease and bossiness.

Ruth had a job offer in Tampa. Dad was going with her. When Marnie and I said goodbye under our mother’s watchful gaze, my sister was smart enough not to let her arms linger too long around our father’s waist. I have never been overly discerning, especially when it comes to matters of the heart, so I folded my body into Dad’s and refused to let go until he pried my fingers loose.

“Hey!” He laughed. “It’s not forever.”

Dad was a good liar. I believed him long enough to let him go.

That night, when Mom served us pie, Marnie’s slice was at least an inch wider than mine, and topped with twice as much whipped cream.

“How come she always gets the bigger slice?” I whined. “It’s not fair.”

My mother spun around from where she was standing at the kitchen sink, rinsing the dinner dishes. Her glower was a bullet straight to my chest. “Life isn’t fair, Virginia. Get used to it.”

Even though my mother was the one to fire that first shot, I blamed my sister. Why wouldn’t I? Mom had chosen Marnie as her ally. I hung my head, ate my meagre ration of pie, and silently plotted my revenge. Later that night, I entered the battlefield of Marnie’s bedroom and performed my first enemy act. I was discovered of course—tried as a traitor and grounded for a week.

My sister never understood why I stole her sterling silver charm bracelet (especially since I had one of my own), and I wasn’t about to explain. Not to her anyway. The truth was I just wanted to feel superior in some small way. Maybe if I’d gotten away with my petty thievery, I’d have felt vindicated and a larger crisis would’ve been averted.

Not likely.

The great sage, Ramana Maharshi, once said, “Whatever is destined not to happen will not happen, try as you may. Whatever is destined to happen will happen, do what you may to prevent it. This is certain.”

Marnie’s and my rivalry was etched into the tablet of fate, as inevitable and unpreventable as a sneeze, and just as explosive. After I got caught with Marnie’s precious bracelet, my sister started locking her bedroom door to keep me out. Fine by me. I’d already locked my heart and there was no way I was letting her inside.

Thomas and I grew up together, but we weren’t friends or anything. He lived three houses down from me and our mothers hated each other. Even if I had been inclined to play with boys, or he with girls, our friendship would have been forbidden. When I was really young, out of obedience to my mother, I walked across the street just to avoid passing by Mrs. Callahan’s house. That was before I discovered how good it felt to be disobedient.

According to Mom, the Callahans were a bunch of degenerates. Marnie and I had better stay away from them. The Callahan boy—a year older than Marnie, two years older than me—was taller than my father, and always struck me as being standoffish. He sat by himself in the back of the bus—too imposing for the cool kids to intimidate, too much of a loner to be inducted into the back-of-the-bussers’ group. Those guys were the perfect mixture of popular and badass. They smoked clove cigarettes and went to make-out parties. Like me, their parents were divorced. Unlike me, they had two sets of full homes instead of one mostly empty one.

I envied them.

When we learned about Rosa Parks in the fourth grade, I never could wrap my head around the irony that, at one point, the front of the bus had been considered desirable.

Marnie sat in the back. It wasn’t surprising. Even out of the house, my sister was everybody’s favorite.

I sat in the middle. I was neither popular nor unpopular. I just sort of was.

It wasn’t until a few weeks before my sixteenth birthday that Tommy Callahan talked to me.