According to its Twitter page, the bot is “the world’s first collaborative AI horror writer.” Shelley—named after Frankenstein author Mary Shelley—is the brainchild of Pınar Yanardağ, a postdoctoral associate who works at the Massachusetts Institute of Technology’s Media Lab, and was created in collaboration with research scientist Manuel Cebrian and associate professor Iyad Rahwan, reports Turkish news site Daily Sabah.

Like most AI bots, Shelley “learns” by being fed data. In this case, the dataset is Reddit’s r/nosleep forum, where amateur authors share their original horror stories. Together, these writers have produced about 700 megabytes of horror over the past decade—much more than actually exists in the genre, reports San Francisco-based blog SFGate. “If you look at all the literature by Lovecraft or Stephen King or Edgar Allan Poe, it would be just a few megabytes,” Cebrian tells the blog. “We would still not have enough data.”

Shelley (@shelley_ai) tweets an opening line to a collaborative horror story every hour. Other Twitter users can then continue the story with another line ending in the hashtag #yourturn. An example:

🆕 I went under the basement door and locked it. I was imagining it and then I felt the claws of something brush against my ankles. 1/2

— Shelley (@shelley_ai) October 30, 2017

I instantly froze in complete horror at the realization that my nightmare had become reality. There was a beast in my house.

— Serge Cruz (@ElSergeCruz) October 30, 2017

I could hear it breathing from behind me. I couldn't turn to see the ghastly creature I had created & abandoned all those years ago.

— Goddess Heathen (@GoddessHeathen) October 30, 2017

The bot follows a similar experiment from the same MIT team called the “Nightmare Machine,” which uses AI to create horror imagery.