Slaughterhouse Wonderland is home to the abandoned mansion that was once owned by California amusement park tycoon Liam Frost. The frost family was known for their several parks all along California known as Summertime Wonderland. The Frost family resided in Burbank, CA where the mansion was built in 1950 by the original founder and Liam's father Thomas Frost. When Thomas died in 1975 the amusement park franchise was left to his only son. This sent a shock wave of controversy across California seeing that Liam suffered from a mental illness known as schizophrenia. Although it was managed by medication, people still feared that Liam wouldn't be as renown as his father.
Despite the many negative throws at Liam, he kept up to his father's legacy and kept Summertime Wonderland running at it's peak. Several years after gaining the franchise he married his wife and had two daughters named Ava and Lilith. Both of his daughters suffered from schizophrenia just as he did. Ava had the form of schizophrenia where she hallucinated and created her own world whereas Lilith believed that she could only eat the raw flesh of something recently dead. Both of the girls were home schooled and heavily medicated to keep their fits under control and for the privacy of the family from the press, Liam had the wall built around the property be raised to twenty feet so that no paparazzi could take a peek. For many years Ava and Lilith would walk to the attic of the mansion so that they could peek over the wall and stare at the outside world that they were forbidden to partake in.
Several weeks after the eldest, Ava, turned eighteen, Liam and his wife died in a fatal car crash. In Liam's will, Ava and Lilith's cousin Marcus was left in charge of the franchise whereas Lilith and Ava were left to live in the mansion and would have a nurse stop by twice a day to give them their medication. Both of the sisters knew deep down that they finally had their freedom and they wouldn't allow themselves to be told what to do and what medication to take anymore. They went home that evening and locked up all the doors and windows and flushed all their pills down the drain. It took a week for the police to un-do all the doors and windows in the house and when they finally reached the door where the girls were hiding they were met with a shotgun. Ava had killed them all and fed them to her sister.
By the time that the police had gotten there both Ava and Lilith had begun to have continuous spurts of their schizophrenia leaving them to be in a constant episode. The only person they would not harm is their cousin Marcus, who came occasionally to drop off food for Ava. Slowly the news came to Burbank of what happened, but no one took care of the situation. They chained up the gate and left the key to Marcus, allowing him to deal with the two himself. Ava slowly turned the mansion into what would become Slaughterhouse Wonderland.
She would sneak out by climbing over the fence and break into hardware stores and steal various things such as saws, chains, rope, etc. to transform her home into the world that her mind created. Lilith had to suffice by eating rabbits and other small animals that made their way into the yard, but slowly began to starve. Wanting to not be alone, Ava started to have to bring in humans to the home for Lilith to eat so that she could have more to eat. It came to Marcus' attention of Lilith's starvation and he would begin to trick teenagers and tourists to go visit the mansion and claim that it was "haunted". Those who were brave were met by Chesire (Ava) and would have to survive the tortures inside the mansion and outside on the property. Those who survived became torturers themselves and those who did not became Lilith's next meal. Hearing of so many people's disappearance in the mansion sparked a legend that spread across the United States and brought more people to the mansion to figure out the mystery of Slaughterhouse Wonderland.