The mystery shack gang are having a bad night but it's about to get worse when a stranger comes to town. An ancient demon is painting the town red literally and the gang is next on his list. Can the Mystery Shack gang make it though the night or will this be their last? A crossover of "Gravity Falls" and the independent film series "Demon Hunters".

The Mystery Kids face off against Coraline's greatest enemy known as the Other Mother. Having returned through sinister circumstances, the Beldam is back and with a terrible vengeance against the girl she so desperately desired as a daughter. Now, it is up to Coraline and the others to fight against the Other Mother and protect Gravity Falls from becoming her new fly on the web.

Dipper and Mabel get a terrifying visit from a new and dangerous foe. However, as it turns out, things get even more interesting when a small group of children with similar experiences towards the supernatural visit the town of Gravity Falls. Now, having to begrudgingly work together, the children must put aside their differences to protect Gravity Falls and all that they hold dear