Kelsier sighed. “Then why was he able to come to the world of the dead?” “It’s not the world of the dead. It’s the world of the mind. Men—all things, truly—are like a ray of light. The floor is the Physical Realm, where that light pools. The sun is the Spiritual Realm, where it begins. This Realm, the Cognitive Realm, is the space between where that beam stretches.”