They had fed me three times by the time the groove was nine inches deep on all sides of the block, and the mortar had hardened. But I was nearly through, I figured. I took a rest, then made another try at loosening the block. I stuck the blade in the slot, levered gently at the stone. If it was only supported on one edge now, as it would be if it were a little less than a foot thick, it should be about ready to go. I couldn't tell. I put down my scraper, got in position, and pushed. I wasn't as strong as I had been; there wasn't much force in the push. Again I rested and again I tried. Maybe there was only a thin crust of mortar still holding; maybe one more ounce of pressure would do it. I took a deep breath, strained ... and felt the block shift minutely. Now! I heaved again, teeth gritted, drew back my feet, and thrust hard. The stone slid out with a grating sound, dropped half an inch. I paused to listen: all quiet. I shoved again, and the stone dropped with a heavy thud to the floor outside. With no loss of time I pushed through behind it, felt a breath of cooler air, got my shoulders free, pulled my legs through ... and stood, for the first time in how many days.... * * * * * I had already figured my next move. As soon as Itzenca had stepped out I reached back in, groped for the water bottle, the dry crusts I had been saving, and the wad of bread paste I had made up. I reached a second time for a handful of the powdered mortar I had produced, then lifted the stone. I settled it in place, using the hard bread as supports, then packed the open joint with gummy bread. I dusted it over with dry mortar, then carefully swept up the debris--as well as I could in the total darkness. The bread-and-water man would have a light and he was due in half an hour or so--as closely as I had been able to estimate the time of his regular round. I didn't want him to see anything out of the ordinary. I was counting on finding Foster filed away somewhere in the stacks, and I'd need time to try to release him. I moved along the corridor, counting my steps, one hand full of bread crumbs and stone dust, the other feeling the wall. There were narrow side branches every few feet; the access ways to the feeding holes. Forty-one paces from my slot I came to a wooden door. It wasn't locked, but I didn't open it. I wasn't ready to use it yet. I went back, passed my hole, continued nine paces to a blank wall. Then I tried the side branches. They were all seven-foot stubs, dead ends; each had the eight-inch holes on either side. I called Foster's name softly at each hole ... but there was no answer. I heard no signs of life, no yells or heavy breathing. Was I the only one here? That wasn't what I had figured on. Foster had to be in one of these delightful bedrooms. I had come across the universe to see him and I wasn't going to leave Bar-Ponderone without him.