Bartol hesitated just for a second before he went onward. The elevator bar had dropped only a few feet before its brakes had stopped it. Bartol lifted himself up to the level of the floor, burned his way through the elevator door, and stepped out into the corridor. He saw the heavy-duty beam-cannon just as the android behind it fired. It was to his right, a few yards down the corridor. The blast of energy roared down the corridor, narrowly missing Bartol as he threw himself back into the elevator. It swung downward, gouging gobbets of flaming metal from the wall, aiming straight for Bartol. There was only one way out of the trap. Bartol switched polarity again and turned his generators up to maximum. It wasn't enough to stop that heavy beam, but-- He leaped over the coruscating beam and literally dived headfirst into the wall on the other side of the corridor. It melted and gassified before him, hardly slowing his plunge. He rolled over and landed on his feet. He kept on running toward the rear wall--through it. He circled through the next room and the next, dodging twice the heavy-duty beams aimed at him. The whole section was becoming a raging inferno; without his body screen, the heat would have been unbearable. At last he came to the wall he was looking for. It shimmered slightly, due to the force field that surrounded it. Just in front of the wall, two androids were swinging a heavy-duty cannon around toward him. He fired his own weapon, but they were shielded by more than the portable shields they wore. This section was _really_ fortified! He dived toward the androids, sliding under the barrel of the projector just as it blazed into white-hot hell. He jumped to his feet and landed a punch on the jaw of the nearest android. It reeled backwards, and the other jumped him. Bartol flipped the second android over his head, slamming it into the face of its partner. They both went down. With two quick blows, he knocked their skulls against the floor. The metal skulls didn't break, but the metal-colloid brain within ceased to function because of the shock. Now came the crucial part. He stepped over to the wall and touched its shimmering surface. It was an ordinary KF-4 field; it had no reactive surface, as did his own. Good! It could be analyzed. The mechanism in the helmet went to work, carefully synchronizing its own vibratory frequency with that of the wall. It was slow work; it would take a full twenty seconds, and in that time, plenty could happen. It was stupid not to build all the walls with force-fields that would make them impervious to beam guns. But then, the whole set-up on Apollyon was stupid. These petty Autarch-Assassin games could only have been set up by a madman. Five android guards ran into the room, firing their beam-rifles. Bartol ignored them; the beams couldn't touch him. Two more started to pull in a wheeled semiportable. They got it in through the door and swiveled it toward Bartol.