"If you will pardon me, sir," the Tenant said to Altamont, "I think it would be a good idea if your companion went up in the flying machine and circled over us, to keep watch for the Scowrers. There are quite a few of them, particularly farther up the rivers, to the east, where the damage was not so great and they can find cellars and shelters and buildings to live in." "Good idea. That way, we won't have to put out guards," Altamont said. "From the looks of this, we'll need every body to help dig into that thing. Hand out one of the portable radios, Jim and go up to about a thousand feet. If you see anything suspicious, give us a yell, then spray it with bullets, and find out what it is afterward." They waited until the helicopter had climbed to position and was circling above, and then turned their attention to the place where the sheet of fused earth and stone bulged upward. It must have been almost ground-zero of one of the hydrogen-bombs: the wreckage of the Cathedral of Learning had fallen predominantly to the north, and the Carnegie Library was tumbled to the east. "I think the entrance would be on this side, toward the Library," Altamont said. "Let's try it, to begin with." He used the solenoid-hammer, slowly pounding a hole in the glaze, and placed a small charge of the plastic explosive. Chunks of the lava-like stuff pelted down between the little mound and the huge one of the old library, blowing a hole six feet in diameter and the two and a half feet deep, revealing concrete bonded with crushed steel-mill slag. "We missed the door," Altamont said. "That means we'll have to tunnel in through who knows how much concrete. Well...." He used a second and larger charge, after digging a hole a foot deep. When he and his helpers came up to look, they found a large mass of concrete blown out, and solid steel behind it. Altamont cut two more holes, one on either side of the blown-out place, and fired a charge in each of them, bringing down more concrete. He found he hadn't missed the door after all. It had merely been concreted over. A few more shots cleared it, and after some work, they got it open. There was a room inside, concrete-floored and entirely empty. Altamont stood in the doorway and inspected the interior with his flashlight; he heard somebody behind him say something about a most peculiar sort of dark-lantern. Across the small room, on the opposite wall, was a bronze plaque. The plaque carried quite a lengthy inscription, including the names of all the persons and institutions participating in the microfilm project. The History Department at the Fort would be interested in that, but the only thing that interested Altamont was the statement that the floor had been laid over the trapdoor leading to the vault where the microfilms were stored. He went outside to the radio.