A picture...that kept running for several minutes. I think I'd eventually like to find a front and a back to it.

...and then he realized, like zooming down and landing on a solid carved block, that the past was real. The zealot movement in first-century Israel had exactly the same sort of reality that the Irish national movement had. The block he - the whole world, actually - was standing on now was the present. He could see the steps gliding down with the smooth noise of rock on rock, opening down out of the bare, recently flat stone floor. This was real. The steps were solid, just as the ages of the past were solid. He could stand on them, and did. He walked down the large, spiraling stairway, reveling in the utter "thereness" of each block under his foot, down into the gray shadows.
She, a bit breathless from her run down from the tower room, stood a moment on the flat floor before the stairway and watched him disappear behind the turn of the wall. She slipped down after him. He was quicker than she thought, but still, she mustn't get too near. She continued to move down stealthily. She wanted to warn him, he who had seen that the steps were there and knew that they must come down now that he knew of their reality. But first she must see what he would do. Timing. Not too close behind, not too far.
He kept going down, down. The steps and walls were all perfectly smooth - not polished-smooth, but not craggy, and a very normal gray. The light stayed gray too, even though he was past where the sunlight should reach. The sound started imperceptibly. It wasn't spooky, or loud, or happy, or sad. A noise of washing waves and faintly ringing bells, and the sound of good thick cloth draping down. It was a very real sound, and yet it gave an unreal attitude to the rock-way, because rocks do not make such sounds.
The sound prepared him for the light. It was the faint blue-yellow of sunlight onto the floor of a pool. It made little webs on the walls and floor - yes, here was a floor again. He had reached the bottom, a round room. The webs were more closely concentrated around a semi-sphere embedded in the center of the smooth, gray, roundly cobblestoned floor. It was obviously the source of the light. It was six inches in diameter. In its surface - a surface like the layer of shellac on wood - were silhouttes of moving cherubim, over the deep clear blue of the globe. Actually, they were rather the opposite of silhouttes, for they were shining a fiery yellow-white light. This light brought an answering light from each of the twelve symbols set on the domed ceiling. Donald reached out, paused, then firmly set his hand to one of the characters. A two foot wide cylindrical hole opened up, centered where the symbol had been. Don was sure it hadn't "appeared," but neither could he recall seeing the rock move the way it had for the steps. A pool of energy, cylindrical, bright and light, stretched from the opening to the spot on the floor directly below. The contstellation Virgo, set in the paving-stones, answered with her own shining. Don looked at it for a moment, nodded, then stepped into the light.
Mara was just in time to see him shoot through the upward tunnel.
Don travelled for about a hundred yards, and came out suddenly on what was apparently the roof of the little domed room. He was standing on a curve that exactly matched the room's ceiling, adding one hundred yards. A roof that thick was ridiculous. Wait - even more ridiculous, there was no such domed formation remotely near Babylon University. He looked around. In the same bright, clean, clear colors of the seraph-globe shone a four foot tall ring of luscious garden all around, through the same shine of shellac. Above it, in semi-circular sections, were several other pictures. One was of a white well against yellow sand. Another was of a hand clasping a lock of wavy chestnut hair. Overhead shone Virgo again, this time set in all her night-sky glory. Brilliant white against deep black. The stars looked, well, not so close that they could be touched, but so real that one would feel more at home with them than stuck to this granite here.
Don considered. Explore the main one first. He stepped through the shining, thin, glass-bubble barrier and into the garden of Eden.
Mara stopped with relief. He had actually taken the right one. Of course, she knew that a thousand variables could still go wrong. But he had taken the right one. Most were commonly curious, and tried to touch the globe. They realized in one moment that their hands could go into it as into water, in the next that no water felt like such a burning, and in the next nothing at all, as far as this earth goes. They were struck dead. Of course the cherubim were only shadows. But a shadow so bright must have as its owner something truly terrible. The great sword guarding. But he had not touched that. There was nothing to do now but return to the library tower-room. Oh, yes. She could ask a blessing of safety. She ran her hands over the much-read words as her heart asked the much-repeated prayer.