I said nothing. Max's nostrils were white and pinched. "Must I make an autopsy?" "Why bother?" I said. "It's obviously heart failure." "Yes, why bother?" he said. He looked tired. "Stay in your cabin, Greta. I'll bring your meals." "I don't trust you." His laughter had a touch of madness. * * * * * _March 10_ Max unlocked my cabin door this morning. He looked drawn. "Listen," he said. "I've checked my respiration, pulse, saliva, temperature. All normal." "So?" "Come here," he said. I followed him into the lab. He indicated a microscope. His eyes were bright. "Well?" "A drop of my blood," he said. "Look." I squinted into the microscope. I saw purple discs. Oddly, they did not attack the red blood cells. There was no fission, no mitosis. The leucocytes, strangely enough, let them alone. My hands were shaking as I took a sterile slide and pricked my finger. I put the slide under the microscope. I adjusted the lens and stared. Purple discs, swimming in my bloodstream. Thriving. Minding their own business. "Me, too," I said. "They're inert," Max said hoarsely. "They don't affect metabolism, cause fever, or interfere with the body chemistry in any way. Do they remind you of anything?" I thought about it. Then I went to the slide file that was marked _flora--negative_. "Right," Max said. "The purple thistle. Spores! The atmosphere is clogged with them. Greta, my sweet, we're infected." "I feel fine," I said. All day long we ran tests. Negative tests. We seem to be disgustingly healthy. "Symbiosis," Max said finally. "Live and let live. Apparently we're hosts." Only one thing disturbs me. Most symbiotes _do_ something for their host. Something to enhance the host's survival potential. We played chess this evening. I won. Max is furious. He's such a poor sport. * * * * * _March 11_ Max talked with Senator Farragut this morning. He gave Epsilon a clean bill of health and the Senator thanked God. "The first starship will leave tonight," the Senator said. "Right on schedule, with ten thousand colonists aboard. You're world heroes!" Max and I played chess the rest of the day. Max won consistently. He utilizes a fianchetto that is utterly impregnable. If he wins tomorrow, I shall have to kill him. * * * * * MAX _March 13_ It was, of course, necessary for me to destroy Armitage and Bishop. They won far too often. But I am sorry about Greta. Yet I had to strangle her. If she hadn't started that infernal queen's pawn opening it would have been different. She beat me six times running, and on the last game I pulled a superb orang-outang, but it was too late. She saw mate in four and gave me that serpent smirk I know so well. How could I have ever been in love with her? * * * * * _March 14_ Frightfully boring to be alone. I have a thought. Chess. Right hand against left. White and black. Jolly good.