When my sister Megan and I sold our grandparents’ house, I thought I had come to terms with saying goodbye to a place that had meant so much to us growing up. The house was old and worn, but every corner held memories—memories of my grandfather teaching me how to fix things, of family gatherings, and lazy afternoons spent listening to the creaks of the floorboards.

Megan, however, wanted to move on. After our grandmother passed, the house no longer felt like home to her. It felt heavy, like it was clinging to the past. I understood, but parting with it wasn’t easy. When we finally sold the house, I thought that chapter of our lives had closed for good.

But then I received a text from the new owners: “Thanks for the extra keys, but what does #1135 mean?”

I was confused. I hadn’t left any extra keys behind. I quickly texted back, asking where they found the keys. “In the kitchen drawer,” they replied. “None of the locks match. We tried every door, but the keys don’t fit.”

A shiver ran down my spine. I hadn’t been in the kitchen much before we sold the house, and Megan had done most of the clearing out. I immediately texted her, asking if she knew anything about the keys. Her reply was alarming: “No, I didn’t leave any keys. They need to get out of the house. NOW.”

I had no idea what was going on, but I knew one thing—something wasn’t right.