Here's an interesting question for you all to ponder. During the DHARMA days, who lives in Ben's house? Clearly whoever it is, knows a bit more than they have shown thus far regarding the Island's secrets. The house certainly seems to have been built around the doorway to the "summoning room." My guess would be Horace or Pierre Chang. Perhaps they didn't know the purpose of the room, but must have known it had some sort of connection to the "Hostiles."