"See and believe," droned the wizard. "Man must believe to accomplish. Form is shadow, substance is illusion, materiality is dream; man is because he believes he is; what is man but a dream of the gods? Yet man can be that which he wishes to be; form and substance, they are but shadows. The mind, the ego, the essence of the god-dream--that is real, that is immortal. See and believe, if you would accomplish, Kull." The king did not fully understand; he never fully understood the enigmatical utterances of the wizard, yet they struck somewhere in his being a dim responsive chord. So day after day he sat before the mirrors of Tuzun Thune. Ever the wizard lurked behind him like a shadow. * * * * * Then came a day when Kull seemed to catch glimpses of strange lands; there flitted across his consciousness dim thoughts and recognitions. Day by day he had seemed to lose touch with the world; all things had seemed each succeeding day more ghostly and unreal; only the man in the mirror seemed like reality. Now Kull seemed to be close to the doors of some mightier worlds; giant vistas gleamed fleetingly; the fogs of unreality thinned; "form is shadow, substance is illusion; they are but shadows" sounded as if from some far country of his consciousness. He remembered the wizard's words and it seemed to him that now he almost understood--form and substance, could not he change himself at will, if he knew the master key that opened this door? What worlds within what worlds awaited the bold explorer? The man in the mirror seemed smiling at him--closer, closer--a fog enwrapped all and the reflection dimmed suddenly--Kull knew a sensation of fading, of change, of merging---- "Kull!" the yell split the silence into a million vibratory fragments! [Illustration: "Kull!" The yell split the silence into a million vibratory fragments.] Mountains crashed and worlds tottered as Kull, hurled back by that frantic shout, made a superhuman effort, how or why he did not know. A crash, and Kull stood in the room of Tuzun Thune before a shattered mirror, mazed and half blind with bewilderment. There before him lay the body of Tuzun Thune, whose time had come at last, and above him stood Brule the Spear-slayer, sword dripping red and eyes wide with a kind of horror. "Valka!" swore the warrior. "Kull, it was time I came!" "Aye, yet what happened?" The king groped for words. "Ask this traitress," answered the Spear-slayer, indicating a girl who crouched in terror before the king; Kull saw that it was she who first sent him to Tuzun Thune. "As I came in I saw you fading into yon mirror as smoke fades into the sky, by Valka! Had I not seen I would not have believed--you had almost vanished when my shout brought you back." "Aye," muttered Kull, "I had almost gone beyond the door that time."