Welcome to the Haunted Mansion: Terrorlands

Sam and Sarah lost their brother, Eric, in an unfamiliar mountain called Highdread Hill. In their search of Eric, they accidentally discovered a mansion.
Too bad, this mansion was no ordinary.
Beneath the mansion laid a forbidden secret...
A secret that they were not meant to know...
Who are those staggering figures in the tunnel? Where do the mysterious red mists in Highdread Hill come from? Why is this village called Dreadland?
Just another urban legend, right?