He looked quickly at the doorway, but the guard had not come back. Leaning forward, he questioned her fiercely. "What are you doing here? They told me yesterday that several people had come down with attacks of Blue Martian. Why aren't you in the hospital with the others?" "Because I wasn't sick!" "But I gave you--" "Imagine how I felt," she raced on, "watching Dr. Haslam start having a chill, hearing Dr. Fauré complain about his awful headache, and listening to Dr. Hudson dial Intercom and call for a doctor. And all that time I was waiting, waiting for something to happen to me. And nothing did! What have you got against me, Dr. Wong, that you infect all the others and only pretend to do it to me? I don't want to grow old any more than they do!" "But I wasn't pretending. Quiet, now, and let me think." He waited until the watchguard had passed by the door, then raised his head. "Look here, Leah. Evidently the infection didn't take. This is what must have happened. That treatment I gave you ten years ago must have made you permanently immune to Blue Martian, and the antibodies it formed in your cells simply protected you against this new invasion of the virus. It never occurred to me that the immunity would last so long. But don't worry, I'll find a way." She looked suspicious. "What do you mean?" "I mean that there's no reason why Blue Martian should be the only vehicle for giving you the SDE. There must be other viruses that will work equally well. It's only a question of finding one." "And how long will that take you?" "How long does anything take in Research? Maybe a week, maybe a year." "And maybe ten! I can't wait, Dr. Wong. I'm thirty-five now; I'm growing older. What good will a long life do me, if it only preserves me as the middle-aged woman I'll be by then? And all those years that I'll be getting older and older, there'll be Tanya, lively and pretty, to remind me that I was once like that, too. I can't face it!" "The watchguard will hear you!" Haggard-faced, he watched her shaking shoulders, hearing her muffled sobs. "You're a criminal, Dr. Wong! It was a crime, what you did to Tanya and me." "I didn't realize in the beginning or I'd never have touched the thing. I know it now, even better than you do, but what can I do?" She looked up and wiped her eyes, her mouth set hard. "I know what I can do. I can report you to the Leader." "What good will that do? You know how terrible you feel now about being left out--though I swear I never meant it to be like this. But just try to imagine. If you report me so that Leader Marley gets the secret of SDE, then thousands of people will be put in just the same situation you are in. You're only one person suffering. But then there'd be hundreds of thousands, millions! Surely you wouldn't want to have that on your conscience?" "Do you think I'd care?"