I thought my son was coming home with a broken heart or a bad roommate story. Instead, he handed me a folded piece of paper from his best friend’s house, and one line on it pulled me straight back to the worst night of my life, eighteen years ago, in a hospital room where I couldn’t see a thing.

Part One: The Door He Locked Behind Him

I was stirring a pot of chili when I heard the front door open.

It was a Thursday evening, barely past six. The kitchen smelled like cumin and onions, and the radio on the windowsill was playing an old song I used to dance to when I was pregnant. I remember thinking how strange it was to cook for one person. For eighteen years, I had made dinner for a boy who ate like three grown men. Now the pot looked ridiculous on the stove.

Then I heard footsteps in the hallway, and I knew them right away.

“Luke?”

My son appeared in the kitchen doorway. He was still wearing his gray hoodie and the denim jacket he’d taken with him when he moved out two days earlier. His eyes were red. His face was blotchy. He looked the way he used to look when he was seven and had fallen off his bike, trying very hard not to cry and failing.

I turned off the stove and pulled out a chair.

“Sit down, sweetheart. What happened?”

He didn’t sit. He stayed by the door, wiping his cheeks with the sleeve of his jacket. Then he did something I’d never seen him do in his own home.

He reached behind him and locked the door.

“Are we alone?” he asked.

“Yes. Of course we’re alone.” I set the wooden spoon down. “Did you and Ben have a fight?”

“No.” He shook his head hard. “Please don’t call him.”

That frightened me more than his tears.

You have to understand who Ben was to us. Luke and Ben had been inseparable since the first week of first grade, when a teacher sat them next to each other because their last names were close in the alphabet and they were the only two boys who refused to take off their rain boots. By the end of that week, they had traded lunches, invented a secret handshake, and announced to both mothers that they were going to live together forever in a treehouse.

They never built the treehouse. But they did nearly everything else together. Soccer. Science fairs. Camping trips. Their first summer jobs at the same grocery store. Ben had his own toothbrush in our bathroom and his own drawer in our hallway closet. When Luke got his wisdom teeth out, it was Ben who sat on the end of the couch feeding him pudding and making him laugh until he begged him to stop.

And people had been calling them twins for years. Same height. Same dark, unruly hair. Same lanky build and same habit of shoving their hands into their back pockets when they were nervous. Teachers mixed them up. Cashiers asked whether they were brothers. Strangers at the soccer field would smile at me and ask, “Are your boys twins?”

We always laughed.

So two days earlier, when Luke had loaded his clothes, his gaming chair, and a box of mismatched dishes into my car and moved into a small two-bedroom apartment across town with Ben, it had felt like the most natural thing in the world. I’d cried in the car afterward, of course. I’d raised him alone since his father died three years ago, and the house had felt enormous without him. But I had been happy for him. Proud of him.

Now he was standing in my kitchen with a locked door at his back, asking me not to call his best friend.

“You and Ben have been friends since you were kids,” I said carefully.

“I know.”

“You were so excited about moving in together. You talked about nothing else for months.”

“I know, Mom.”

“People have been calling you two twins for years.”

Luke finally looked at me. His voice was very quiet.

“That’s part of the problem.”