"Nadine. That's nice. Holmes.... I'm Earl Frye, up until a few minutes ago a quiet research scientist who stays in his lab practically twenty-four hours a day. Nadine Holmes. Were you really small a few minutes ago--or did I imagine it?" "Yes. I was small.... So _you_ are Dr. Earl Frye...." "Yes. But how can you know me?" Earl asked, surprised at her tone. A distant knocking sounded. He groaned. "That's probably Irene," he said. "She'll pound the door down. You stay here and be quiet while I get rid of her. She could cause both of us a lot of trouble." He went to the door, slipped out, and carefully locked it. The knocking was peremptory at the lab door. "Just a minute!" he said. He unlocked the door, prepared to tell Irene she was interrupting some important work. It wasn't Irene. "Oh, it's you, Mrs. Glassman. I didn't know. I was busy and didn't want to be interrup--that is, come on in." He opened the door invitingly, and glanced worriedly at the door to his living quarters. Had he locked it? Of course he had. He distinctly remembered locking it. "I'm sorry I interrupted your work," Mrs. Glassman said. "I met Irene--Dr. Conner, you know. She told me you might need some reminding about dinner--seven thirty. I do hope you'll be there." "I may not have my work done," Earl said weakly. "Nonsense! It can wait. It will do you good to get away from the lab for an evening. If you aren't there I'll come and get you." "Okay," Earl said hastily. "I promise to be there--on time." He locked the hall door after Mrs. Glassman. * * * * * He glanced thoughtfully at the pump bench with its ten sets of glass threads containing ten different fluids, ready for cutting and connecting to the test instruments for measurement of speed and sustainment of molecular chain action. The theory of what he was looking for--what all ten of the scientists were looking for in their planned exploration of a few dozen thousand substances, was fairly simple. The molecule in theory had to be of a special type, of which there were many examples. It had to consist of two parts; one larger than the other, such that the smaller part could break off easily and jump to the next molecule, combining with it and freeing its counterpart on that next molecule, so that the freed part would repeat the performance on the next, and so on. In that way, the ion of the lesser molecular part, starting at one end of the chain of identical molecules, would start a chain of reactions which would end in an identical free ion at the farther end of the glass thread. In effect it would be the same as though the free ion had passed quickly through the full length of the fine tube--without any of the molecules actually having moved at all. Unfortunately, so far, none of the substances tried had behaved quite as they should in theory. It was impossible to get a tube fine enough for a thread one molecule thick, with the molecules lined up properly.