Ascaban

I was thinking of writing an SCP that functioned as an event that occurred once a year on Halloween. I plan on there being a group that runs a haunted house attraction with the intent of kidnapping children to a alternate reality.

But the twist would be once they enter this reality they would be completely forgotten about as if they never existed in our reality. The reality people enter i haven't fully thought of yet, this is where i need the most help as i want this world to be some steam punk world or a kind of fantasy medieval world.

Eventually the foundation found that their are 3 waves that caused relatively minor changes in reality on Halloween every year. Since the waves happen with half hourly intervals (the time it takes per haunted house group to be taken through and stolen) the foundation find the location of the event one year and send in a task force.

A exploration log begins where they enter the haunted house and the reality where over 7 months the team takes notes and eventually escapes back to our reality. I want this group to arrive back at Site-?? and be completely ignored by the perimeter patrols since these people where completely forgotten and don't exist. The Foundation reads through there notes (and perhaps by sending drones to SCP-2935 to check that realities computers for information) decide to take back the task force.

My only issues is that i cannot decide on how the force returns to our reality and the nature of the reality except that i want it to be in a Steam Punk / Medieval-Fantasy Setting.