"He existed in all the many dimensions of the multiverse. Yet he, in common with all others, was bound by the dimension of Time. He had cast off the chains of space but was tied, as perhaps all denizens of the multiverse would always be, by the imperturbable prowl of Time, which brooked no halt, which condoned no tampering with its movement, whether to slow it or to speed it. Time, the changer, could not be changed. Space, perhaps, the material environment, could be conquered. Time, never."