At 2 a.m., my sister collapsed in front of my door, covered in bruises, shaking, and clinging to her daughter in a wheelchair. Then my phone lit up with a message from our mother telling me not to help them. I ignored it, let them in, and just by looking at them I knew this was serious. I called 911 immediately, and that was just the beginning.

PART 1: THE KNOCK ON THE DOOR

“Don’t help that crippled girl. Your sister brought it on herself.”

That was the message my mom sent me at 2:04 a.m., just as Valeria was bleeding profusely in my living room and her nine-year-old daughter, Camila, was trembling in her wheelchair by the door.

Three minutes earlier, I was half asleep in my apartment in Iztapalapa, watching an old series with a cup of cold coffee, when someone started banging on the door as if their life depended on it.

These weren’t normal knocks.

They were desperate blows.

“Mariana, please! Open up!”

It was Valeria.

When I opened the door, my sister collapsed against me. Her lip was split, one eye was swollen, her blouse was torn at the shoulder, and one arm was pressed against her body as if breathing hurt. Behind her stood Camila, silent, her eyes wide, clutching a silver locket so tightly the chain had already etched itself into her palm.

I quickly put them inside, double-locked the door, and propped a chair against it without thinking.

“You’re here now,” I told her. “No one’s going to touch you.”

Valeria let out a dry, broken laugh.

“Don’t promise things you can’t keep.”

I went to get the first-aid kit, but when I saw her ribs, I knew that wasn’t something that could be fixed with gauze. She had finger-shaped bruises on her arm and a cut on her side. Camila wasn’t crying. That was what scared me the most. Children who live peacefully cry. Those who have learned to be afraid stay still.

Then my cell phone vibrated.

Mom.