«All right. Let's go play bait.»

Blade and Saorm climbed down the vines from a rear window on the second floor. Then they hurried around to the front, to find the robot still standing there. It couldn't get into the building and its enemies wouldn't come out. So Blade and Saorm took cover half a block up the street, then opened fire with their rifles.

Instantly the robot turned its head, its body followed the head around with surprising speed, and the laser chewed a piece out of the wall above the two men. A fragment large enough to crush Blade's skull came close enough to part his hair. Before the robot could fire again, Blade and Saorm were running up the street. Both hoped it would follow. After a moment's hesitation, it did. In fact it came after them so fast that Blade looked back to find it gaining on them rapidly. They were both zigzagging, but in another minute it would be too close for safety.

«To the right!» Saorm followed Blade's gesture and darted down a side-street with the Englishman at his heels. The robot saw them turning but fired too late. A section of the corner building two stories high crashed down and spread itself across the street in smoking rubble. More of the building was tottering. Blade stopped in the shelter of a doorway, hoping to see the robot come close enough to be caught by the next fall of masonry.

Instead it gave the building a wide berth. When the collapse did come the robot was already well out of danger and advancing on Blade. As it marched out of the cloud of dust and smoke, its laser fired again. A chunk of pavement flew up like a soccer ball, crashed into the front of a building just ahead of Blade, and brought down several large pieces of metal facing. Blade and Saorm barely jumped aside in time, and Blade was now painfully aware that two could play this game of dropping buildings on the enemy. He decided to keep to the main streets as much as possible and use the side streets only for cover. The robot could turn so well that there was no reason to try leading it around sharp corners and hope it would fall or crash into a building.

Blade and Saorm headed west as fast as they could, nearly getting lost several times but usually drawing the robot after them. Twice it seemed to lose track of them, and once Blade saw it turn back toward the east. Assuming it was turning back toward the Kaldakans, he opened fire, was nearly killed by the robot's laser, but at least got its attention again.

Blade wondered why the laser was fixed in the robot's chest rather than mounted in the swiveling head. He could only guess that the black muzzle in the head was some sort of close-range weapon, perhaps a grenade launcher. He hoped it was empty. A few grenades could have finished the Kaldakans, and one lucky shot could do the job on him and Saorm. On the other hand, lasers worked only on line-of-sight. You couldn't fire them in a curve over anything or through anything too solid.

Of course this worked both ways. Blade and Saorm had to expose themselves to fire at the robot. They were smaller targets, but they were much more vulnerable. There didn't seem to be any part of the robot they could hurt with the rifles, at least before the robot could bring its own heavier weapon to bear. Blade quickly knew that he and Saorm were going to have to win by skill rather than by strength.

Several times Blade tried to lead the robot across the bridges over Gilmarg's numerous canals, hoping its weight would collapse a bridge under it. Each time the robot stopped at the head of the bridge. Each time Blade had to recross the canal before he could get the robot moving again. He hoped the Kaldakans were on their way out of the city by now, but he couldn't be sure. At least he hadn't heard any laser fire from the east, so the robot was probably operating alone.

Blade did notice that when the robot turned its head, its feet sometimes kept going for several more steps in the old direction. This happened often enough to make Blade wonder if the robot's computer «brain» was slightly defective. After all these years it very well might be, and this could give him and Saorm an opening. There should be places where the banks of the canals which criss-crossed Gilmarg were so overgrown with foliage that they were hidden. If they led the robot straight toward one of those places, then suddenly drew its attention to one side, the robot's legs would continue to take it forward a few more steps, and then…

They were far enough ahead of the robot now so that Blade could lead Saorm into a doorway and force him to sit down for a minute. The merchant was gasping for breath.

«I'll need you for our next trick,» said Blade. «But if that doesn't work, I want you to give up this chase.»

«My honor-my daughter-I'm just a bit short-of-breath.»

«You'll drop dead if you go on much longer,» said Blade sharply. «I'd rather bring you home to Geyrna than tell her how gallantly you died! Now, is there a place where the canal bank is so overgrown that the robot might not see it until too late?»

There was, and Saorm led Blade toward it as quickly as the robot would let them go. They could never forget the searing green death licking at their heels, and Blade was beginning to worry. Saorm really did look ready to fall over, and he himself wasn't going to be able to play hide and seek with this mechanical monster forever. Human flesh could not compete with steel and electricity in an endurance contest.

Then they were out on the bank high above the canal and trotting rapidly along the street toward the park where Saorm had said there would be a good place to set their trap. As the robot turned onto the street half a mile behind them, Blade saw something peculiar about the pavement ahead. For fifty yards the pavement slabs of the street were tilted slightly toward the canal. Blade looked across the canal. There were actually two streets, an upper and a lower roadway one above the other, supported by the steel columns. He then looked over the railing along the street on his side of the canal. It was the same on this side. Those shaky pavement blocks ahead hid a fifteen-foot drop to the roadway below.

That should be enough, and suddenly Blade had a different plan. The trap in the park forgotten for the moment, Blade quickly gave Saorm his instructions, conscious of the robot tramping steadily toward them. The merchant staggered off toward the next bridge, his eyes so glazed with fatigue Blade wondered if he could even see the robot, let alone hit it. Well, with luck he wouldn't need to hit it to draw its attention.

Then the robot was within range and Blade began his dance of death with it. He darted back and forth across the street high above the canal, never stopping even to fire his rifle, always watching the robot, always seeing it tramp steadily forward, firing every few yards. He began to fear it would step on one of the loose slabs and spring the trap prematurely.

Now the robot needed only about ten more steps before it reached the loose slabs. «Fire,» Blade whispered to Saorm. «Fire!» He wanted to scream, but his throat felt as if someone was firing a miniature laser inside it. His chest felt as tight as if the robot was already gripping him in one hand.

«Fire!»

Green light speared out from a window on the far side of the canal. The robot's head swiveled to scan the direction of the new attack, while its feet took the last few steps onto the first of the loose blocks.

For a moment Blade couldn't be sure his trick had worked. Then several tons of robot made the slab give up its long struggle against the force of gravity. Instead of tilting toward the canal, the slab tilted toward the buildings inland. It tilted so slowly that for another moment Blade thought the robot might have time to step backward. The robot stopped, sensed that something was wrong, and lifted a foot for a backward step. Then the slab cracked completely in two, and the robot vanished as if it had fallen through a trapdoor.