The “glass box” operation in New York, which we now know the Double set up through a series of cutouts, suggests he was after something else as well. Some kind of entity that moved, as Briggs appeared to be able to do, free of the constraints of time and space as we used to think we understood them. Something monstrous and murderous that appeared in that box and slaughtered those two kids who had the horrible misfortune of being there when it appeared. From the evidence we’ve seen, the only familiar word that comes to mind to properly describe this entity is “demonic.” And the glass box appears to have been installed there as a trap to catch it.