Cracks In The Window
The Kiln is an extra dimensional space outside of the continuum of parallel Earths. Since the vacuum of space and interplay of singularities affects space-time, the Kiln only governs the multiple versions of Earth. From inside the Kiln, Gaffer can pull people from their Earth to the Kiln and transport people from the Kiln to various Earths.
It has a variety of living quarters for its variety of agents, each one tailored to the specific needs of each member. There are program-able rooms within the Kiln that can create training simulations and realistic terrain features. Food, clothing, and weapons can be manufactured and by rooms within the Kiln but cannot be taken outside of it.