Vault 666 is a haunted house at the Six Flags Magic Mountain's annual Fright Fest Halloween events. Located behind Full Throttle Plaza, Vault 666 takes visitors inside an abandoned secret government research facility that once conducted genetic experiments crossing humans with animals. Upon entering a storage warehouse filled with crates and boxes marked "Corrosive" and "Fragile", things suddenly comes to life as items on the shelves start rattling and rumbling -- all triggered at random intervals by monsters hiding in secret compartments. Stepping inside a power-control room, the lights dim as a man is electrocuted by a loose wire amid arcing electrical sound and lighting effects. Inside a chain-link cage, a 10-foot-tall rear projection video screen teeming with zombie silhouettes tilts precariously toward visitors as they try to escape the temporary prison.

Throughout the immersive Vault 666, visitors are splashed with blood from a crimson pool, blasted with steam from a busted pipe and startled by oil barrels rattling noisily to life. Each room is wisely separated by heavy-duty meat locker dividers, which provide cover for maze monsters to reset for the next scare. In the distance is an old abandoned facility that has recently been discovered with years of secrets of the unknown. If you dare to enter, be aware of your surroundings at all times. Unknown animal like screams have been heard deep within the unsecured vault.

Vault 666's official description looks like the following:

"Mr. and Mrs. Ramp owned a hardware store in a small town just 30 minutes north of Los Angeles. They had the sweetest, smartest child, but rumor had it the little one was mentally unbalanced due to being harassed by classmates. The family hardware store was located on a secluded street around the corner from the school. Many parents would send their kids to buy small nick-knacks on their way home.

Kids around town suddenly started disappearing. Police went to all the nearby businesses, showing photos of of their loved ones to ask if they had seen any of them. The Ramp's always denied any recognition of the missing faces, even knowing of their offspring's social problems. One night, an off-duty police officer was walking home when he heard a murderous scream coming from the hardware shop. He banged on the door, and a voice yelled "we're closed!" The officer bust down the door and headed to the back storage room, where he saw the most gruesome sight. He opened the door and found lifeless heads and bodies, some detached, hanging from the ceiling. In the shadows, a figure was just about to saw off the head of the most recent missing person!

The murderous minor had suffered mental trauma as a result of an unbalanced upbringing and unwarranted harassment. The Ramp's pleaded and the authorities and agreed to send their child to the local sanitarium. Instead, the demented Ramp child escaped to an abandoned vault that was once a government research facility that conducted genetic experiments crossing humans with animals. Needless to say, a whole new world of torment and suffering began by the corrupt and abusive child.

Some try their hardest to get out…. but it always was too late. How about you? Will you escape?"