I found it. After weeks of searching, I finally found what she was trying to show me. It was in the attic of my grandmother's old house, tucked inside a dusty box of forgotten memories. A letter, yellowed with age, addressed to someone named "M."

The girl with the red umbrella hasn't appeared since that day in March. I've walked past that corner every evening, camera in hand, but she's gone. Or maybe she was never there at all. But this letter... this letter is real. I can feel its weight in my hands, the delicate paper crinkling as I unfold it.

"Dear M," it begins, "If you're reading this, it means you've found your way home." My hands are shaking as I read the words, written in a flowing script I don't recognize. The letter speaks of a promise made long ago, of a secret kept for generations. It mentions a key, hidden somewhere in the house, and a door that only opens on the night of the full moon.

I don't know what to make of it. The letter isn't signed, and the date is smudged beyond recognition. But something about it feels familiar, like a dream I can't quite remember. Maybe that's why the girl with the red umbrella led me here. Maybe she knew I needed to find this.

Tomorrow, I'm going back to the house. I'll search every corner, every hidden space, until I find that key. Because somehow, I know this isn't just an old letter. This is the beginning of something bigger, something that might explain why I've been seeing a girl who shouldn't exist.