The old grey house

You and a group of friends had nothing better to do and are no strangers from getting into trouble. There is an old rumor, in the outskirts of the town there is an old gray manor, their owners perished in a horrible way, the culprit was never found, over time many people went inside, surprisingly few came back, utterly traumatized. Some say the owners messed with sonething they couldn't understand and whatever caused still the dissapearances haunts the place, others have witnessed strange things roaming around. You thought they were probably just some stupid made up stories and you are no chicken, so going into the town's famous gray house would be fun, right?