open pattern, obscuring the sight of him more effectively than any fog-cloud could have done. When his simpler instruments told him that the ship tailing him was quite lost in the Greek fire he sprayed out a flock of tiny, powerfully explosive pellets.
There was one blast and it was all over; the tailing ship was dispersed through space, and whatever had been its crew was lost beyond repair.
Having effected this, Bartok set his motors to idling in the direction of the invasion star and lit a cigarette, waiting in almost perfect calm to be detected and taken in tow.
He did not have long to wait; there were half a dozen ships on him in twenty minutes. They clamped onto him what he realized must be the perfected tractor ray, so long celebrated in song and story and never yet seen on any spaceway till now.
As the tractors dragged him through space towards Arided he inspected very closely the ships that were applying it. They were six in number; as Babe had said they were remarkable for the fact that they were quite open, being no more than a power-unit around which was built a framework containing emplacements for weapons of all sorts and conditions. There were cat-walks as well, up and down which scuttled nasty things about the size and very nearly the shape of men.
Bartok was baffled by the metallic sheen of the things when it hit him that they were robots. "Damned clever," he mused. "Damned clever indeed. They don't need air, they don't need a commissariat; all they need is orders and oil. I wish we'd thought up that gag a few centuries ago!"
They landed him skillfully and easily on the fourth planet. As Bartok looked about he realized slowly that Babe hadn't been under any hallucinations when she'd sworn that the engineering works that had been run up were the most remarkable things in the unknown universe. There were towers everywhere, great patches of concrete for landing and servicing ships; long lines of them hanging in the air waiting for room. Not one square inch of ground space except narrow cat-walks could be seen free of any mechanism. What was not transmission gears was solar engine; what was not solar engine was unimaginably complex calculators clicking and buzzing away as robots stalked among them to tear off results and deliver them to the nearest building.
Bartok got out of his ship; immediately a gang of robots sprang to attention after the fashion of a guard of honor. Bartok had never seen robots before; there were enough hands to do the work of the colonial system and the social problems that would have been raised caused any experimentation with robots to be frowned on by the executive committee. And where was the executive committee today? God only knew. It was a very sure bet that if any of it was left this residue would be mopped up by the despised and strictly forbidden mechanical men. Somebody had beaten the colonial system to the punch. But who could it be?
Commander Bartok nearly swooned when a robot-in-command came up to him and said in perfect, though toneless English: "Pray excuse this temporary detention, Wing Commander. I can assure you that it shall be terminated in a brief while."
The brief while extended itself into three days before they would tell him what was going on. During that time he had the run of a delightful apartment which lacked only books and magazines for his comfort and relaxation. Apparently to substitute for them the robot-in-chief, or whoever was in charge, sent in robots whose
