On a couch opposite the doorway three men sat talking. Two others stood before them. The moment we entered, the conversation stopped abruptly.

"Beth?" said a tall, graying man. He was already stuffing papers into a bag. "Back so soon?"

He wasn't really listening for a reply and Beth didn't make one. When he had the papers in the bag he locked it, then snapped it around his wrist and put the key in his pocket.

"We'll continue this at the lab," he said to the men. "I'll be along in just a few minutes." Then he came up to us.

"I see you've replaced your blond young man," he smiled.

I knew all about this man who stood before me, with his stooped shoulders and keen eyes. Eldeth Copperd would have been surprised at the extent of my knowledge. I even knew why his government considered it wise to have several of its security agents near him at all times.

"Can't you stay a minute and get acquainted with Marko?" Beth was saying. "He's really a remarkable fellow. He can swim faster than you or I could run."

"Literally? That would be quite fast."

"Literally."

He looked at me with sudden interest and I was sorry the conversation had taken that turn. I didn't want those keen eyes examining me too closely. They might note the absence of skin porosity.

Copperd didn't notice, but I made a mental note to watch my step. And another not to go swimming again. Beth would be watching me, and if she were close enough she might see the webbing pop out between my fingers and toes when I got into the water.

"That's my father," Beth said after he and I had shaken hands and he had left. "Demands exactness. He's a scientist, you know. A physicist."

"Oh?" I said. As if I hadn't known. "Is he always this busy?"

"Busier. If he isn't working at the lab till all hours, he's working at home in his study. Or having conferences. The only time I have him alone and to myself is Sunday evening."

That was the information I had been hoping for.

Beth and I sat on the couch her father had vacated. We talked. I watched my words carefully; there were a good many commonplace things I knew nothing about. And I didn't want any more questions about myself. Fortunately, conversation between a young man and a young woman is much the same everywhere. I didn't have to pretend I was interested in Beth. She was unusually attractive. And she seemed to find me so.

We talked a bit, laughed a good deal, and when I got up to leave I knew that I had done well in the initial stage. But there was still a good deal to be done.

"May I see you tonight?" I asked. "Just a 'coke date'."

That was an expression I'd heard and had taken the trouble to make certain I understood. It seemed to be just the thing in the present case.

"I'd like that," Beth said. "Pick me up about nine."

Her choice of time could not have been more suitable. I was out of money. There was Mrs. Mara to be paid, and now the cost of the evening's entertainment.

Until darkness fell I could do nothing about that. So I went back to my room and read old newspapers I had collected. I had discovered on my first day that those were the best sources of information. Those and the moving pictures.

For one who must learn a great deal about a people in a short time there is one infallible way: watch them in their favorite sports and relaxations. The moving pictures and the comic strips had been invaluable. In another few weeks I could have passed anywhere.

At eight o'clock it was growing dark. I changed my shirt, put on a sport coat and left the room. Five minutes later I was walking down a quiet street that was lined with fashionable homes.

After that it was merely a question of time. I went around the block, found that it was still too light, and went around again, this time slowly.

There was only one man on the street on my next time around. I sized him up quickly and decided that he was prosperous. He came on toward me. I managed to be