The Refining Room is a recurring room that is found via a hole in the wall in Haunting Ground. Fiona Belli, although hesitant to explore it at first, easily slips through. These rooms can be found whenever there is a hole present - only Fiona can enter; Hewie will wait outside (which poses the risk of him taking off by himself and Fiona would then need to find him) and stalkers can't enter and/or attack her while inside. There is a small pedestal in the corner called the Perpetuum Machina (Perpetuity Machine) that will produce Magnesia or Antimony Powder if the player needs them.