A Florida teenager said to be obsessed with a fictional demon-like character named Slender Man allegedly set fire to her home early Thursday morning as her family slept inside.

Lily Marie Hartwell, 14, took a bedsheet and towel and soaked it with rum and bleach before setting them on fire inside her Port Richey home a little before 2 a.m., police said according to the New York Daily News.

Hours before the fire, Hartwell got into an argument with her mother about doing chores.

Her mother and 9-year-old brother, who were asleep when the blaze was set, were alerted to the flames by a smoke alarm and ran outside, the newspaper reported. When the mom realized her daughter was missing, she tried to reenter the home but the fire was too intense.

The mom later received a text from Hartwell saying, "Mom, I'm so sorry. I don't know why I did it." She also asked if anyone was injured, the Daily News reported.

It took firefighters several hours to subdue the flames. They went inside to search for the teen, but she was nowhere to be found.

Hartwell was eventually located and arrested. She was sleeping in a nearby park bathroom she walked to after allegedly setting the fiery trap. The teen admitted to setting the fire on purpose after arguing with her mother, according to The Suncoast News.

Police found evidence that Hartwell had a fascination with the Slender Man, a mythological being with supernatural powers fashioned from online horror fiction. The same character is believed to have motivated two pre-teen girls accused of nearly stabbing their friend to death earlier this year.

Hartwell told investigators she often visited websites like creepypasta.com that described horrific acts committed by the fictional character.

"Keep out," she wrote in her journal according to the Tampa Bay Times. "If this keeps up there will be no safety in this house."

Hartwell was charged with one count of arson and two counts of attempted murder. She remains held at the Pasco Juvenile Assessment Center.